diff --git a/158.326 Software Architecture.sln b/158.326 Software Architecture.sln
index de24ede..fb345a2 100644
--- a/158.326 Software Architecture.sln	
+++ b/158.326 Software Architecture.sln	
@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.31515.178
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31710.8
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "158326 Week 7 Singletons", "158326 Week 7 Singletons\158326 Week 7 Singletons.csproj", "{DDB32161-79F3-4CCF-9CCC-44CCD562B15E}"
 EndProject
@@ -23,6 +23,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tutorial 5", "Tutorial 5\Tu
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tutorial 6", "Tutorial 6\Tutorial 6.csproj", "{00702453-3AD5-4822-A38C-2859B52C3E4C}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tutorial 9", "Tutorial 9\Tutorial 9.csproj", "{38781F4C-0A86-42F7-8912-D17CF5E0FDED}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tutorial 9 Tests", "Tutorial 9 Tests\Tutorial 9 Tests.csproj", "{5198ABA9-CBE2-4AEF-95D5-F14705697294}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -69,6 +73,14 @@ Global
 		{00702453-3AD5-4822-A38C-2859B52C3E4C}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{00702453-3AD5-4822-A38C-2859B52C3E4C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{00702453-3AD5-4822-A38C-2859B52C3E4C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{38781F4C-0A86-42F7-8912-D17CF5E0FDED}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{38781F4C-0A86-42F7-8912-D17CF5E0FDED}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{38781F4C-0A86-42F7-8912-D17CF5E0FDED}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{38781F4C-0A86-42F7-8912-D17CF5E0FDED}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5198ABA9-CBE2-4AEF-95D5-F14705697294}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5198ABA9-CBE2-4AEF-95D5-F14705697294}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5198ABA9-CBE2-4AEF-95D5-F14705697294}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5198ABA9-CBE2-4AEF-95D5-F14705697294}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/158326 Week 7 Singletons/Program.cs b/158326 Week 7 Singletons/Program.cs
index 0630e10..d350ee4 100644
--- a/158326 Week 7 Singletons/Program.cs	
+++ b/158326 Week 7 Singletons/Program.cs	
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 
 namespace _158326_Week_7_Singletons
@@ -10,6 +11,58 @@ namespace _158326_Week_7_Singletons
             Console.WriteLine("158.326 Software Architecture");
             Console.WriteLine("\tWeek 7 - Singleton Design Pattern");
             Console.WriteLine("\tSingletons are instanced classes that can have only 0 or 1 instances of that class in existance in the application (Multitons are a variant that restricts the maximum number of instances)");
+            Console.WriteLine("\nCompany:");
+            for (int i = 0; i < 10; i++)
+            {
+                try
+                {
+                    Company instanceOfCompany = Company.GetCompany();
+                    Console.WriteLine(instanceOfCompany.ShowDetails());
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e.Message);
+                }
+            }
+            Console.WriteLine("\nFileSingleton:");
+            for (int i = 0; i < 10; i++)
+            {
+                try
+                {
+                    FileSingleton instanceOfCompany = FileSingleton.GetInstance(i);
+                    Console.WriteLine(instanceOfCompany.ShowDetails());
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e.Message);
+                }
+            }
+            for (int i = 100; i < 110; i++)
+            {
+                try
+                {
+                    FileSingleton instanceOfCompany = FileSingleton.GetInstance(i);
+                    Console.WriteLine(instanceOfCompany.ShowDetails());
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e.Message);
+                }
+            }
+            Console.WriteLine("\nCompany:");
+            for (int i = 0; i < 10; i++)
+            {
+                try
+                {
+                    Company instanceOfCompany = Company.GetCompany();
+                    Console.WriteLine(instanceOfCompany.ShowDetails());
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e.Message);
+                }
+            }
+
         }
     }
 
@@ -23,14 +76,15 @@ namespace _158326_Week_7_Singletons
         /// Store the instance in a private, static variable
         /// </summary>
         private static FileSingleton instance;
+        private string _name;
 
         /// <summary>
         /// Path of the file to open
         /// </summary>
-        public static Uri FilePath { get; set; } = new Uri("\\log.txt", UriKind.Relative); // Opens exactly one file stream on log.txt and will always return that stream
+        //public static Uri FilePath { get; set; } = new Uri("\\log.txt", UriKind.Relative); // Opens exactly one file stream on log.txt and will always return that stream
 
         // We can define instance variables here:
-        public FileStream OpenedFileStream { get; set; } // Calling FileSingleton.GetInstance().OpenedFileStream will always return this object
+       // public FileStream OpenedFileStream { get; set; } // Calling FileSingleton.GetInstance().OpenedFileStream will always return this object
 
 
         // We can also define  
@@ -40,20 +94,68 @@ namespace _158326_Week_7_Singletons
         /// This restricts the creation of this instance to local methods, so by restricting constructor calls
         /// to GetInstance(), we can ensure that only one instance is created
         /// </summary>
-        private FileSingleton() { }
+        private FileSingleton(int i) 
+        {
+            _name = i.ToString();
+        }
 
         
         /// <summary>
         /// Gets the initialised instance of FileSingleton
         /// </summary>
         /// <returns></returns>
-        public static FileSingleton GetInstance()
+public static FileSingleton GetInstance(int i)
+{
+    if (instance is null)
+    {
+        instance = new FileSingleton(i);
+    }
+    return instance;
+}
+
+        public string ShowDetails()
         {
-            if (instance is null)
+            return _name;
+        }
+    }
+
+    public sealed class Company
+    {
+        private string _name;
+        private static Company _company;
+        private bool _legalInstance;
+        private List<string> _listEmployee;
+
+        private Company()
+        {
+            if (_company == null)
             {
-                instance = new FileSingleton();
+                _company = this;
+                _name = "test";
+                _legalInstance = true;
+            }
+            else
+            {
+                _legalInstance = false;
+            }
+            
+        }
+
+        public static Company GetCompany()
+        {
+            return new Company();
+        }
+
+        public string ShowDetails()
+        {
+            if (_legalInstance)
+            {
+                return _name;
+            }
+            else
+            {
+                throw new ApplicationException("Null Object");
             }
-            return instance;
         }
     }
 }
diff --git a/Tutorial 5/CurrentConditionsDisplay.cs b/Tutorial 5/CurrentConditionsDisplay.cs
index 72d2a2b..a10b417 100644
--- a/Tutorial 5/CurrentConditionsDisplay.cs	
+++ b/Tutorial 5/CurrentConditionsDisplay.cs	
@@ -13,13 +13,20 @@ namespace Tutorial_5
     public partial class CurrentConditionsDisplay : Form, IWeatherObserver, IDisplay
     {
         ISubject subject;
-        WeatherData weatherData;
+        //WeatherData_old weatherData;
         private void RegisterButton_Click(object sender, EventArgs e)
         {
             subject.RegisterObserver(this);
         }
 
         double temperature = default, humidity = default, pressure = default;
+
+        /// <summary>
+        /// Push technique
+        /// </summary>
+        /// <param name="temperature"></param>
+        /// <param name="humidity"></param>
+        /// <param name="pressure"></param>
         public void Update(double temperature, double humidity, double pressure)
         {
             this.temperature = temperature;
@@ -30,9 +37,9 @@ namespace Tutorial_5
 
         public void UpdateOther()
         {
-            this.temperature = weatherData.GetTemperature();
-            this.humidity = weatherData.GetHumidity();
-            this.pressure = weatherData.GetPressure();
+            //this.temperature = weatherData.GetTemperature();
+            //this.humidity = weatherData.GetHumidity();
+            //this.pressure = weatherData.GetPressure();
         }
 
         public void Display()
diff --git a/Tutorial 5/ForecastDisplay.Designer.cs b/Tutorial 5/ForecastDisplay.Designer.cs
new file mode 100644
index 0000000..8e5a737
--- /dev/null
+++ b/Tutorial 5/ForecastDisplay.Designer.cs	
@@ -0,0 +1,98 @@
+
+namespace Tutorial_5
+{
+    partial class ForecastDisplay
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.label2 = new System.Windows.Forms.Label();
+            this.ConditionLabel = new System.Windows.Forms.Label();
+            this.RegisterButton = new System.Windows.Forms.Button();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif", 16F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.label1.Location = new System.Drawing.Point(100, 9);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(96, 26);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Forecast";
+            // 
+            // label2
+            // 
+            this.label2.AutoSize = true;
+            this.label2.Location = new System.Drawing.Point(14, 106);
+            this.label2.Name = "label2";
+            this.label2.Size = new System.Drawing.Size(104, 13);
+            this.label2.TabIndex = 1;
+            this.label2.Text = "Expected Conditions";
+            // 
+            // ConditionLabel
+            // 
+            this.ConditionLabel.AutoSize = true;
+            this.ConditionLabel.Location = new System.Drawing.Point(124, 106);
+            this.ConditionLabel.Name = "ConditionLabel";
+            this.ConditionLabel.Size = new System.Drawing.Size(139, 13);
+            this.ConditionLabel.TabIndex = 2;
+            this.ConditionLabel.Text = "______________________";
+            // 
+            // RegisterButton
+            // 
+            this.RegisterButton.Location = new System.Drawing.Point(85, 231);
+            this.RegisterButton.Name = "RegisterButton";
+            this.RegisterButton.Size = new System.Drawing.Size(136, 23);
+            this.RegisterButton.TabIndex = 3;
+            this.RegisterButton.Text = "Register Observer";
+            this.RegisterButton.UseVisualStyleBackColor = true;
+            // 
+            // ForecastDisplay
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(304, 450);
+            this.Controls.Add(this.RegisterButton);
+            this.Controls.Add(this.ConditionLabel);
+            this.Controls.Add(this.label2);
+            this.Controls.Add(this.label1);
+            this.Name = "ForecastDisplay";
+            this.Text = "ForecastDisplay";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private System.Windows.Forms.Label label1;
+        private System.Windows.Forms.Label label2;
+        private System.Windows.Forms.Label ConditionLabel;
+        private System.Windows.Forms.Button RegisterButton;
+    }
+}
\ No newline at end of file
diff --git a/Tutorial 5/ForecastDisplay.cs b/Tutorial 5/ForecastDisplay.cs
new file mode 100644
index 0000000..c5c926f
--- /dev/null
+++ b/Tutorial 5/ForecastDisplay.cs	
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace Tutorial_5
+{
+    public partial class ForecastDisplay : Form
+    {
+        public ForecastDisplay()
+        {
+            InitializeComponent();
+        }
+    }
+}
diff --git a/Tutorial 5/Form1.resx b/Tutorial 5/ForecastDisplay.resx
similarity index 100%
rename from Tutorial 5/Form1.resx
rename to Tutorial 5/ForecastDisplay.resx
diff --git a/Tutorial 5/Form1.cs b/Tutorial 5/Form1.cs
deleted file mode 100644
index 505320d..0000000
--- a/Tutorial 5/Form1.cs	
+++ /dev/null
@@ -1,43 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Data;
-using System.Drawing;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows.Forms;
-
-namespace Tutorial_5
-{
-    public partial class Form1 : Form
-    {
-        ISubject subject;
-        public Form1()
-        {
-            InitializeComponent();
-            this.subject = new WeatherData();
-
-            
-        }
-
-        private void Form1_Load(object sender, EventArgs e)
-        {
-           
-        }
-
-        private void SliderChanged(object sender, EventArgs e)
-        {
-            subject.NotifyObservers();
-            TemperatureLabel.Text = TemperatureSlider.Value.ToString() + " ℃";
-            HumidityLabel.Text = HumiditySlider.Value.ToString() + " %";
-            PressureLabel.Text = PressureSlider.Value.ToString() + " kPa";
-        }
-
-        private void Form1_Load_1(object sender, EventArgs e)
-        {
-            CurrentConditionsDisplay ccd = new CurrentConditionsDisplay(this.subject);
-            ccd.Show();
-        }
-    }
-}
diff --git a/Tutorial 5/Program.cs b/Tutorial 5/Program.cs
index a69b8c9..c316cd1 100644
--- a/Tutorial 5/Program.cs	
+++ b/Tutorial 5/Program.cs	
@@ -16,7 +16,7 @@ namespace Tutorial_5
         {
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
-            Application.Run(new Form1());
+            Application.Run(new WeatherData());
 
         }
     }
diff --git a/Tutorial 5/Tutorial 5.csproj b/Tutorial 5/Tutorial 5.csproj
index cb9e440..8f10130 100644
--- a/Tutorial 5/Tutorial 5.csproj	
+++ b/Tutorial 5/Tutorial 5.csproj	
@@ -51,11 +51,17 @@
     <Compile Include="CurrentConditionsDisplay.Designer.cs">
       <DependentUpon>CurrentConditionsDisplay.cs</DependentUpon>
     </Compile>
-    <Compile Include="Form1.cs">
+    <Compile Include="ForecastDisplay.cs">
       <SubType>Form</SubType>
     </Compile>
-    <Compile Include="Form1.Designer.cs">
-      <DependentUpon>Form1.cs</DependentUpon>
+    <Compile Include="ForecastDisplay.Designer.cs">
+      <DependentUpon>ForecastDisplay.cs</DependentUpon>
+    </Compile>
+    <Compile Include="WeatherData.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="WeatherData.Designer.cs">
+      <DependentUpon>WeatherData.cs</DependentUpon>
     </Compile>
     <Compile Include="IDisplay.cs" />
     <Compile Include="IObserver.cs" />
@@ -63,12 +69,14 @@
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ThirdPartyDisplay.cs" />
-    <Compile Include="WeatherData.cs" />
     <EmbeddedResource Include="CurrentConditionsDisplay.resx">
       <DependentUpon>CurrentConditionsDisplay.cs</DependentUpon>
     </EmbeddedResource>
-    <EmbeddedResource Include="Form1.resx">
-      <DependentUpon>Form1.cs</DependentUpon>
+    <EmbeddedResource Include="ForecastDisplay.resx">
+      <DependentUpon>ForecastDisplay.cs</DependentUpon>
+    </EmbeddedResource>
+    <EmbeddedResource Include="WeatherData.resx">
+      <DependentUpon>WeatherData.cs</DependentUpon>
     </EmbeddedResource>
     <EmbeddedResource Include="Properties\Resources.resx">
       <Generator>ResXFileCodeGenerator</Generator>
diff --git a/Tutorial 5/Form1.Designer.cs b/Tutorial 5/WeatherData.Designer.cs
similarity index 99%
rename from Tutorial 5/Form1.Designer.cs
rename to Tutorial 5/WeatherData.Designer.cs
index a682f29..b94ddf5 100644
--- a/Tutorial 5/Form1.Designer.cs	
+++ b/Tutorial 5/WeatherData.Designer.cs	
@@ -1,7 +1,7 @@
 
 namespace Tutorial_5
 {
-    partial class Form1
+    partial class WeatherData
     {
         /// <summary>
         /// Required designer variable.
diff --git a/Tutorial 5/WeatherData.cs b/Tutorial 5/WeatherData.cs
index 89de336..29aa6ba 100644
--- a/Tutorial 5/WeatherData.cs	
+++ b/Tutorial 5/WeatherData.cs	
@@ -1,12 +1,16 @@
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using System.Windows.Forms;
 
 namespace Tutorial_5
 {
-    class WeatherData : ISubject
+    public partial class WeatherData : Form, ISubject
     {
         List<IWeatherObserver> observers;
         public void DeregisterObserver(IWeatherObserver observer)
@@ -15,6 +19,9 @@ namespace Tutorial_5
             else Console.Error.WriteLine("{0} does not exist in the observers list.", observer.ToString());
         }
 
+        /// <summary>
+        /// 'Push' method
+        /// </summary>
         public void NotifyObservers()
         {
             double t = GetTemperature();
@@ -23,7 +30,7 @@ namespace Tutorial_5
 
             foreach (var observer in observers)
             {
-                observer.Update(t,h,p);
+                observer.Update(t, h, p);
             }
         }
 
@@ -35,17 +42,17 @@ namespace Tutorial_5
 
         public double GetTemperature()
         {
-            return 0.0;
+            return TemperatureSlider.Value;
         }
 
         public double GetHumidity()
         {
-            return 0.0;
+            return HumiditySlider.Value;
         }
 
         public double GetPressure()
         {
-            return 0.0;
+            return PressureSlider.Value;
         }
 
         void MeasurementChanged()
@@ -55,7 +62,33 @@ namespace Tutorial_5
 
         public WeatherData()
         {
+            InitializeComponent();
             observers = new List<IWeatherObserver>();
         }
+
+        private void Form1_Load(object sender, EventArgs e)
+        {
+           
+        }
+
+        /// <summary>
+        /// Analagous to the Update() method in Excercise 1
+        /// Pushes data to observers via Subject.NotifyObservers
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void SliderChanged(object sender, EventArgs e)
+        {
+            NotifyObservers();
+            TemperatureLabel.Text = TemperatureSlider.Value.ToString() + " ℃";
+            HumidityLabel.Text = HumiditySlider.Value.ToString() + " %";
+            PressureLabel.Text = PressureSlider.Value.ToString() + " kPa";
+        }
+
+        private void Form1_Load_1(object sender, EventArgs e)
+        {
+            CurrentConditionsDisplay ccd = new CurrentConditionsDisplay(this);
+            ccd.Show();
+        }
     }
 }
diff --git a/Tutorial 5/WeatherData.resx b/Tutorial 5/WeatherData.resx
new file mode 100644
index 0000000..1af7de1
--- /dev/null
+++ b/Tutorial 5/WeatherData.resx	
@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>
\ No newline at end of file
diff --git a/Tutorial 9 Tests/Properties/AssemblyInfo.cs b/Tutorial 9 Tests/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..3c6c916
--- /dev/null
+++ b/Tutorial 9 Tests/Properties/AssemblyInfo.cs	
@@ -0,0 +1,20 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+[assembly: AssemblyTitle("Tutorial 9 Tests")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("Tutorial 9 Tests")]
+[assembly: AssemblyCopyright("Copyright ©  2021")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+[assembly: ComVisible(false)]
+
+[assembly: Guid("5198aba9-cbe2-4aef-95d5-f14705697294")]
+
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/Tutorial 9 Tests/Tutorial 9 Tests.csproj b/Tutorial 9 Tests/Tutorial 9 Tests.csproj
new file mode 100644
index 0000000..b5f70bb
--- /dev/null
+++ b/Tutorial 9 Tests/Tutorial 9 Tests.csproj	
@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.props" Condition="Exists('..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.props')" />
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{5198ABA9-CBE2-4AEF-95D5-F14705697294}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Tutorial_9_Tests</RootNamespace>
+    <AssemblyName>Tutorial 9 Tests</AssemblyName>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">15.0</VisualStudioVersion>
+    <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
+    <ReferencePath>$(ProgramFiles)\Common Files\microsoft shared\VSTT\$(VisualStudioVersion)\UITestExtensionPackages</ReferencePath>
+    <IsCodedUITest>False</IsCodedUITest>
+    <TestProjectType>UnitTest</TestProjectType>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="Microsoft.VisualStudio.TestPlatform.TestFramework, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\MSTest.TestFramework.2.1.2\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.dll</HintPath>
+    </Reference>
+    <Reference Include="Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>..\packages\MSTest.TestFramework.2.1.2\lib\net45\Microsoft.VisualStudio.TestPlatform.TestFramework.Extensions.dll</HintPath>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="UnitTest1.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Tutorial 9\Tutorial 9.csproj">
+      <Project>{38781f4c-0a86-42f7-8912-d17cf5e0fded}</Project>
+      <Name>Tutorial 9</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets" Condition="Exists('$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets')" />
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.props'))" />
+    <Error Condition="!Exists('..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.targets'))" />
+  </Target>
+  <Import Project="..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.targets" Condition="Exists('..\packages\MSTest.TestAdapter.2.1.2\build\net45\MSTest.TestAdapter.targets')" />
+</Project>
\ No newline at end of file
diff --git a/Tutorial 9 Tests/UnitTest1.cs b/Tutorial 9 Tests/UnitTest1.cs
new file mode 100644
index 0000000..61c4d15
--- /dev/null
+++ b/Tutorial 9 Tests/UnitTest1.cs	
@@ -0,0 +1,28 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using Tutorial_9;
+
+namespace Tutorial_9_Tests
+{
+    [TestClass]
+    public class UnitTest1
+    {
+        [TestMethod]
+        public void SedanNoDiscountTest()
+        {
+            Sedan sedan = new Sedan();
+            Assert.AreEqual(0, sedan.PriceAfterDays(0));
+            Assert.AreEqual(80, sedan.PriceAfterDays(1));
+            Assert.AreEqual(320, sedan.PriceAfterDays(4));
+        }
+
+        [TestMethod]
+        public void TestCarTest()
+        {
+            TestCar sedan = new TestCar();
+            Assert.AreEqual(0, sedan.PriceAfterDays(0));
+            Assert.AreEqual(0, sedan.PriceAfterDays(1));
+            Assert.AreEqual(0, sedan.PriceAfterDays(4));
+        }
+    }
+}
diff --git a/Tutorial 9 Tests/packages.config b/Tutorial 9 Tests/packages.config
new file mode 100644
index 0000000..f84cb10
--- /dev/null
+++ b/Tutorial 9 Tests/packages.config	
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="MSTest.TestAdapter" version="2.1.2" targetFramework="net472" />
+  <package id="MSTest.TestFramework" version="2.1.2" targetFramework="net472" />
+</packages>
\ No newline at end of file
diff --git a/Tutorial 9/Properties/AssemblyInfo.cs b/Tutorial 9/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..836e892
--- /dev/null
+++ b/Tutorial 9/Properties/AssemblyInfo.cs	
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("Tutorial 9")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("Tutorial 9")]
+[assembly: AssemblyCopyright("Copyright ©  2021")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("38781f4c-0a86-42f7-8912-d17cf5e0fded")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]
diff --git a/Tutorial 9/Rental.cs b/Tutorial 9/Rental.cs
new file mode 100644
index 0000000..e4fd94f
--- /dev/null
+++ b/Tutorial 9/Rental.cs	
@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Tutorial_9
+{
+    public abstract class Car
+    {
+        protected abstract decimal Price { get; }
+        public decimal PriceAfterDays(decimal numDays)
+        {
+            decimal result;
+            if (numDays < 0 || numDays >= 90) throw new ArgumentOutOfRangeException("Provided number of days is invalid");
+            if (numDays < 5)
+            {
+                result = Price * numDays;
+            }
+            else if (numDays < 10)
+            {
+                result = Price * numDays * 0.9M;
+            }
+            else if (numDays < 20)
+            {
+                result = Price * numDays * 0.85M;
+            }
+            else
+            {
+                result = Price * numDays * 0.8M;
+            }
+            return result;
+        }
+    }
+
+    public class Hatchback : Car
+    {
+        protected override decimal Price => 50;
+    }
+
+    public class Sedan : Car
+    {
+        protected override decimal Price => 80;
+    }
+
+    public class Convertible : Car
+    {
+        protected override decimal Price => 100;
+    }
+
+    public class Saloon : Car
+    {
+        protected override decimal Price => 120;
+    }
+    public class Motorcycle : Car
+    {
+        protected override decimal Price => 20;
+    }
+}
diff --git a/Tutorial 9/Tutorial 9.csproj b/Tutorial 9/Tutorial 9.csproj
new file mode 100644
index 0000000..7feea4f
--- /dev/null
+++ b/Tutorial 9/Tutorial 9.csproj	
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{38781F4C-0A86-42F7-8912-D17CF5E0FDED}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Tutorial_9</RootNamespace>
+    <AssemblyName>Tutorial 9</AssemblyName>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Net.Http" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Rental.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+</Project>
\ No newline at end of file