diff --git a/gradebook/src/GradeBook/Book.cs b/gradebook/src/GradeBook/Book.cs
index bfe7932..01cee3d 100644
--- a/gradebook/src/GradeBook/Book.cs
+++ b/gradebook/src/GradeBook/Book.cs
@@ -3,7 +3,7 @@ using System.Collections.Generic;
 
 namespace GradeBook
 {
-    class Book
+    public class Book
     {
         private List<double> grades;
         private string name;
diff --git a/gradebook/test/GradeBook.Tests/BookTests.cs b/gradebook/test/GradeBook.Tests/BookTests.cs
new file mode 100644
index 0000000..9687807
--- /dev/null
+++ b/gradebook/test/GradeBook.Tests/BookTests.cs
@@ -0,0 +1,22 @@
+using System;
+using Xunit;
+using GradeBook;
+
+namespace GradeBook.Tests
+{
+    public class BookTests
+    {
+        [Fact]
+        public void Test1()
+        {
+            // arrange
+            var book = new Book("");
+            book.AddGrade(89.1);
+            book.AddGrade(90.5);
+            book.AddGrade(77.3);
+            
+            // act
+            book.ShowStaticstics();
+        }
+    }
+}
diff --git a/gradebook/test/GradeBook.Tests/GradeBook.Tests.csproj b/gradebook/test/GradeBook.Tests/GradeBook.Tests.csproj
index 89e935f..8f1c1c9 100644
--- a/gradebook/test/GradeBook.Tests/GradeBook.Tests.csproj
+++ b/gradebook/test/GradeBook.Tests/GradeBook.Tests.csproj
@@ -19,4 +19,8 @@
     </PackageReference>
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\GradeBook\GradeBook.csproj" />
+  </ItemGroup>
+
 </Project>
diff --git a/gradebook/test/GradeBook.Tests/UnitTest1.cs b/gradebook/test/GradeBook.Tests/UnitTest1.cs
deleted file mode 100644
index c837976..0000000
--- a/gradebook/test/GradeBook.Tests/UnitTest1.cs
+++ /dev/null
@@ -1,14 +0,0 @@
-using System;
-using Xunit;
-
-namespace GradeBook.Tests
-{
-    public class UnitTest1
-    {
-        [Fact]
-        public void Test1()
-        {
-            Assert.Equal(1,0);
-        }
-    }
-}