This might work

src/test/java/rocks/zipcode/quiz5/fundamentals/calculator/AddTest.java

@@ -11,7 +11,7 @@ public class AddTest {
     @Test
     public void test1() {
         // given
-        test(98.5, 10.5, 88.5);
+        test(99.0, 10.5, 88.5);
     }
 
     @Test
@@ -44,6 +44,6 @@ public class AddTest {
         Double actual = calculator.add(input1, input2);
 
         // then
-        Assert.assertEquals(expected, actual, 0);
+        Assert.assertEquals(expected, actual, 0.01);
     }
 }

src/test/java/rocks/zipcode/quiz5/fundamentals/calculator/DivideTest.java

@@ -29,7 +29,7 @@ public class DivideTest {
     @Test
     public void test4() {
         // given
-        test(9.0, 63.0, 5.0);
+        test(12.6, 63.0, 5.0);
     }
 
     @Test
@@ -44,6 +44,6 @@ public class DivideTest {
         Double actual = calculator.divide(input1, input2);
 
         // then
-        Assert.assertEquals(expected, actual, 0);
+        Assert.assertEquals(expected, actual, 0.01);
     }
 }

src/test/java/rocks/zipcode/quiz5/fundamentals/calculator/SquareRootTest.java

@@ -40,6 +40,6 @@ public class SquareRootTest {
         Double actual = calculator.squareRoot(input);
 
         // then
-        Assert.assertEquals(expected, actual, 0);
+        Assert.assertEquals(expected, actual, 0.01);
     }
 }

src/test/java/rocks/zipcode/quiz5/fundamentals/calculator/SquareRootsTest.java

@@ -24,7 +24,7 @@ public class SquareRootsTest {
     @Test
     public void test3() {
         // given
-        test(new Double[]{12.0, 438.0, }, 144.0, 191844.0, 81.0);
+        test(new Double[]{12.0, 438.0, 9.0}, 144.0, 191844.0, 81.0);
     }
 
     @Test

src/test/java/rocks/zipcode/quiz5/fundamentals/calculator/SquareTest.java

@@ -44,6 +44,6 @@ public class SquareTest {
         Double actual = calculator.square(input);
 
         // then
-        Assert.assertEquals(expected, actual, 0);
+        Assert.assertEquals(expected, actual, 0.01);
     }
 }

src/test/java/rocks/zipcode/quiz5/fundamentals/stringutils/HasDuplicateConsecutiveCharactersTest.java

@@ -8,7 +8,7 @@ public class HasDuplicateConsecutiveCharactersTest {
     @Test
     public void test1() {
         String input = "Happy";
-        Assert.assertFalse(StringUtils.hasDuplicateConsecutiveCharacters(input));
+        Assert.assertTrue(StringUtils.hasDuplicateConsecutiveCharacters(input));
     }
 
     @Test

src/test/java/rocks/zipcode/quiz5/objectorientation/bankaccount/DepositPositiveTest.java

@@ -17,28 +17,28 @@ public class DepositPositiveTest {
 
     @Test(expected = IllegalArgumentException.class)
     public void test2() {
-        test(10.0, 50.0);
+        test(10.0, -50.0);
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void test3() {
-        test(55.0, 500.0);
+        test(55.0, -500.0);
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void test4() {
-        test(78.0, 90.0);
+        test(78.0, -90.0);
     }
 
-    public void test(Double initialBalance, Double witdrawalAmount) {
+    public void test(Double initialBalance, Double depositAmount) {
         // given
-        Double expected = initialBalance + witdrawalAmount;
+        Double expected = initialBalance + depositAmount;
         BankAccount bankAccount = new BankAccount();
         Transactable transactable = (Transactable)bankAccount;
         bankAccount.setBalance(initialBalance);
 
         // when
-        transactable.deposit(witdrawalAmount);
+        transactable.deposit(depositAmount);
         Double actual = transactable.getBalance();
 
         // then

src/test/java/rocks/zipcode/quiz5/objectorientation/employee/EmployeePolymorphismTest.java

@@ -24,8 +24,8 @@ public class EmployeePolymorphismTest {
     }
 
 
-    @Test
+    @Test(expected = ClassCastException.class)
     public void test3() {
-        Assert.assertFalse((Account) (Object) employee instanceof Account);
+        Account account = (Account) (Object) employee;
     }
 }