diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem10.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem10.java
index ea10a3d..3a1c9c4 100644
--- a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem10.java
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem10.java
@@ -36,7 +36,7 @@ public class TestProblem10 extends BaseTest{
 		//Verify result
 		assertEquals(142913828922L, problem.getSum());
 		assertEquals("The sum of all the primes < 2000000 is 142913828922", problem.getResult());
-		//Verify the porblem variables and functions were called
+		//Verify the problem variables and functions were called
 		verifyProblem(problem);
 
 		//Verify the problem won't be run again
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem11.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem11.java
new file mode 100644
index 0000000..8f98a03
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem11.java
@@ -0,0 +1,62 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem11 extends BaseTest{
+	@InjectMocks
+	private Problem11 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getNumbers(); });
+		assertThrows(Unsolved.class, () -> { problem.getProduct(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(List.of(89, 94, 97, 87), problem.getNumbers());
+		assertEquals(70600674, problem.getProduct());
+		assertEquals(String.format("The greatest product of 4 numbers in a line is 70600674%nThe numbers are [89, 94, 97, 87]"), problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem12.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem12.java
new file mode 100644
index 0000000..6461379
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem12.java
@@ -0,0 +1,64 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem12 extends BaseTest{
+	@InjectMocks
+	private Problem12 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("What is the value of the first triangle number to have over 500 divisors?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getTriangularNumber(); });
+		assertThrows(Unsolved.class, () -> { problem.getLastNumberAdded(); });
+		assertThrows(Unsolved.class, () -> { problem.getDivisorsOfTriangularNumber(); });
+		assertThrows(Unsolved.class, () -> { problem.getNumberOfDivisors(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(76576500, problem.getTriangularNumber());
+		assertEquals(12375, problem.getLastNumberAdded());
+		assertEquals(576, problem.getDivisorsOfTriangularNumber().size());
+		assertEquals(576, problem.getNumberOfDivisors());
+		assertEquals("The triangular number 76576500 is the sum of all numbers >= 12375 and has 576 divisors", problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the porblem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem13.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem13.java
new file mode 100644
index 0000000..3a90ccc
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem13.java
@@ -0,0 +1,60 @@
+package com.mattrixwv.project_euler.problems;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.math.BigInteger;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem13 extends BaseTest{
+	@InjectMocks
+	private Problem13 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("Work out the first ten digits of the sum of the one-hundred 50-digit numbers", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getNumbers(); });
+		assertThrows(Unsolved.class, () -> { problem.getSum(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(100, problem.getNumbers().size());
+		assertEquals(new BigInteger("5537376230390876637302048746832985971773659831892672"), problem.getSum());
+		assertEquals(String.format("The sum of all 100 numbers is 5537376230390876637302048746832985971773659831892672%nThe first 10 digits of the sum of the numbers is 5537376230"), problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem14.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem14.java
new file mode 100644
index 0000000..17d1032
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem14.java
@@ -0,0 +1,60 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem14 extends BaseTest{
+	@InjectMocks
+	private Problem14 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("Which starting number, under 1000000, produces the longest chain using the iterative sequence?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getLength(); });
+		assertThrows(Unsolved.class, () -> { problem.getStartingNumber(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(525, problem.getLength());
+		assertEquals(837799, problem.getStartingNumber());
+		assertEquals("The number 837799 produced a chain of 525 steps", problem.getResult());
+		//Verify the porblem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the porblem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem15.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem15.java
new file mode 100644
index 0000000..e75d549
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem15.java
@@ -0,0 +1,61 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem15 extends BaseTest{
+	@InjectMocks
+	private Problem15 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("How many routes from the top left corner to the bottom right corner are there through a 20x20 grid if you can only move right and down?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assumeTrue(Boolean.valueOf(System.getProperty("longTests")));
+		assertThrows(Unsolved.class, () -> { problem.getNumberOfRoutes(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(137846528820L, problem.getNumberOfRoutes());
+		assertEquals("The number of routes is 137846528820", problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		assumeTrue(Boolean.valueOf(System.getProperty("longTests")));
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem16.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem16.java
new file mode 100644
index 0000000..2259ad1
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem16.java
@@ -0,0 +1,56 @@
+package com.mattrixwv.project_euler.problems;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem16 extends BaseTest{
+	@InjectMocks
+	private Problem16 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("What is the sum of the digits of the number 2^1000?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getSum(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(1366, problem.getSum());
+		assertEquals(String.format("2^1000 = 10715086071862673209484250490600018105614048117055336074437503883703510511249361224931983788156958581275946729175531468251871452856923140435984577574698574803934567774824230985421074605062371141877954182153046474983581941267398767559165543946077062914571196477686542167660429831652624386837205668069376%nThe sum of the elements is 1366"), problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem17.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem17.java
new file mode 100644
index 0000000..b86036e
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem17.java
@@ -0,0 +1,56 @@
+package com.mattrixwv.project_euler.problems;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem17 extends BaseTest{
+	@InjectMocks
+	private Problem17 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("If all the numbers from 1 to 1000 inclusive were written out in words, how many letters would be used?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getLetterCount(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(21124, problem.getLetterCount());
+		assertEquals("The sum of all the letters in all the numbers 1-1000 is 21124", problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem18.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem18.java
new file mode 100644
index 0000000..fe504a9
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem18.java
@@ -0,0 +1,56 @@
+package com.mattrixwv.project_euler.problems;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem18 extends BaseTest{
+	@InjectMocks
+	private Problem18 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("Find the maximum total from top to bottom", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getTotal(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(1074, problem.getTotal());
+		assertEquals("The value of the longest path is 1074", problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem19.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem19.java
new file mode 100644
index 0000000..49c191f
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem19.java
@@ -0,0 +1,58 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem19 extends BaseTest{
+	@InjectMocks
+	private Problem19 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("How many Sundays fell on the first of the month during the twentieth century (1 Jan 1901 to 31 Dec 2000)?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getTotalSundays(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(171, problem.getTotalSundays());
+		assertEquals("There are 171 Sundays that landed on the first of the months from 1901 to 2000", problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}
diff --git a/src/test/java/com/mattrixwv/project_euler/problems/TestProblem20.java b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem20.java
new file mode 100644
index 0000000..511eb23
--- /dev/null
+++ b/src/test/java/com/mattrixwv/project_euler/problems/TestProblem20.java
@@ -0,0 +1,60 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem20 extends BaseTest{
+	@InjectMocks
+	private Problem20 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("What is the sum of the digits of 100!?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getNumber(); });
+		assertThrows(Unsolved.class, () -> { problem.getNumberString(); });
+		assertThrows(Unsolved.class, () -> { problem.getSum(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(648, problem.getSum());
+		assertEquals(String.format("100! = 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000%nThe sum of the digits is: 648"), problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}