diff --git a/src/main/java/com/zipcodewilmington/assessment2/part1/BasicUtilities.java b/src/main/java/com/zipcodewilmington/assessment2/part1/BasicUtilities.java
index 1402353..c1b0c4f 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part1/BasicUtilities.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part1/BasicUtilities.java
@@ -2,18 +2,20 @@
 
 public class BasicUtilities {
     public Boolean isGreaterThan5(Integer value) {
-        return null;
+        return value >= 5;
     }
 
     public Boolean isLessThan7(Integer value) {
-        return null;
+        return value <= 7;
     }
 
     public Boolean isBetween5And7(Integer valueToEvaluate) {
-        return null;
+        return isGreaterThan5(valueToEvaluate) && isLessThan7(valueToEvaluate);
     }
 
     public Boolean startsWith(String string, Character character) {
-        return null;
+        if (string.toLowerCase().charAt(0) == character) return true;
+        if (string.toUpperCase().charAt(0) == character) return true;
+        return string.charAt(0) == character;
     }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part1/IntegerArrayUtilities.java b/src/main/java/com/zipcodewilmington/assessment2/part1/IntegerArrayUtilities.java
index a360000..a3285aa 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part1/IntegerArrayUtilities.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part1/IntegerArrayUtilities.java
@@ -1,19 +1,34 @@
 package com.zipcodewilmington.assessment2.part1;
 
+
 public class IntegerArrayUtilities {
     public Boolean hasEvenLength(Integer[] array) {
-        return null;
+        return array.length % 2 == 0;
     }
 
+
     public Integer[] range(int start, int stop) {
-        return null;
+
+        int counter = 0;
+        for (int i = start; i < stop; i++) {
+            counter++;
+        }
+
+        Integer[] arr = new Integer[counter + 1];
+        int counter2 = 0;
+        for (int k = start; k <= stop; k++) {
+            arr[counter2] = k;
+            counter2++;
+        }
+        return arr;
     }
 
+
     public Integer getSumOfFirstTwo(Integer[] array) {
-        return null;
+        return array[0] + array[1];
     }
 
     public Integer getProductOfFirstTwo(Integer[] array) {
-        return null;
+        return array[array.length - 1] * array[array.length - 2];
     }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part1/WuTangConcatenator.java b/src/main/java/com/zipcodewilmington/assessment2/part1/WuTangConcatenator.java
index 63f210e..d11f2c1 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part1/WuTangConcatenator.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part1/WuTangConcatenator.java
@@ -1,18 +1,22 @@
 package com.zipcodewilmington.assessment2.part1;
 
 public class WuTangConcatenator {
+
+    Integer input;
+
     public WuTangConcatenator(Integer input) {
+        this.input = input;
     }
 
     public Boolean isWu() {
-        return null;
+        return this.input % 3 == 0;
     }
 
     public Boolean isTang() {
-        return null;
+        return this.input % 5 == 0;
     }
 
     public Boolean isWuTang() {
-        return null;
+        return this.input % 15 == 0;
     }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part2/ArrayUtility.java b/src/main/java/com/zipcodewilmington/assessment2/part2/ArrayUtility.java
index de2f799..9e92b67 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part2/ArrayUtility.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part2/ArrayUtility.java
@@ -1,19 +1,79 @@
 package com.zipcodewilmington.assessment2.part2;
 
+
+import java.util.HashMap;
+import java.util.Map;
+
+
 public class ArrayUtility {
+
+
     public Integer[] merge(Integer[] array1, Integer[] array2) {
-        return null;
+        Integer[] newArr = new Integer[array1.length + array2.length];
+        int counter = 0;
+
+        for (int i = 0; i < array1.length; i++) {
+            newArr[i] = array1[i];
+            counter++;
+        }
+        for (int j = 0; j < array2.length; j++) {
+            newArr[counter++] = array2[j];
+        }
+        return newArr;
     }
 
+
     public Integer[] rotate(Integer[] array, Integer index) {
-        return null;
+
+        for (int i = 0; i < index; i++) {
+            int k;
+            int temp = array[0];
+
+            for (k = 0; k < array.length - 1; k++) {
+                array[k] = array[k + 1];
+            }
+            array[k] = temp;
+        }
+        return array;
     }
 
+
     public Integer countOccurrence(Integer[] array1, Integer[] array2, Integer valueToEvaluate) {
-        return null;
+        int counter = 0;
+        int counter2 = 0;
+
+        for (Integer value1 : array1) {
+            if (value1.equals(valueToEvaluate)) counter++;
+        }
+        for (Integer value2 : array2) {
+            if (value2.equals(valueToEvaluate)) counter2++;
+        }
+        return counter + counter2;
     }
 
+
     public Integer mostCommon(Integer[] array) {
-        return null;
+        Map<Integer, Integer> map = new HashMap<>();
+
+        for (int i = 0; i < array.length; i++) {
+            Integer key = array[i];
+            if (map.containsKey(key)) {
+                Integer freq = map.get(key);
+                freq++;
+                map.put(key,freq);
+            } else {
+                map.put(key,1);
+            }
+        }
+
+        Integer maxCount = 0;
+        Integer result = -1;
+        for(Map.Entry<Integer, Integer> val : map.entrySet()) {
+            if (maxCount < val.getValue()) {
+                result = val.getKey();
+                maxCount = val.getValue();
+            }
+        }
+        return result;
     }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part2/ListUtility.java b/src/main/java/com/zipcodewilmington/assessment2/part2/ListUtility.java
index e978685..862c331 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part2/ListUtility.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part2/ListUtility.java
@@ -1,29 +1,54 @@
 package com.zipcodewilmington.assessment2.part2;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class ListUtility {
-    public Boolean add(int i) {
-        return null;
-    }
 
-    public Integer size() {
-        return null;
+    List<Integer> list;
+
+    public ListUtility() {
+        this.list = new ArrayList<>();
     }
 
+
+    public Boolean add(Integer i) { return list.add(i); }
+
+
+    public Integer size() { return list.size(); }
+
+// TODO: getUnique
     public List<Integer> getUnique() {
+        List<Integer> list2 = new ArrayList<>();
+        for (Integer inter : list2) {
+            list2.add(inter);
+        }
         return null;
     }
 
+
     public String join() {
-        return null;
+        Integer[] result = new Integer[list.size()];
+        for (int i = 0; i < result.length; i++) {
+            result[i] = list.get(i);
+        }
+        return Arrays.toString(result).replaceAll("\\[|]|", "");
     }
 
+
     public Integer mostCommon() {
-        return null;
+
+        ArrayUtility arrayUtility = new ArrayUtility();
+        Integer[] result = new Integer[list.size()];
+        for (int i = 0; i < result.length; i++) {
+            result[i] = list.get(i);
+        }
+        return arrayUtility.mostCommon(result);
     }
 
+
     public Boolean contains(Integer valueToAdd) {
-        return null;
+        return list.contains(valueToAdd);
     }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part2/Router.java b/src/main/java/com/zipcodewilmington/assessment2/part2/Router.java
index 2267425..503e680 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part2/Router.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part2/Router.java
@@ -1,20 +1,47 @@
 package com.zipcodewilmington.assessment2.part2;
 
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+
 public class Router {
+
+    Map<String, String> map;
+
+    public Router() { this.map = new LinkedHashMap<>(); }
+
     public void add(String path, String controller) {
+        map.put(path, controller);
     }
 
     public Integer size() {
-        return null;
+        return this.map.size();
     }
 
     public String getController(String path) {
-        return null;
+        return this.map.get(path);
     }
 
     public void update(String path, String studentController) {
+        this.map.replace(path, studentController);
     }
 
     public void remove(String path) {
+        this.map.remove(path);
+    }
+
+
+    // TODO: toString
+    @Override
+    public String toString() {
+
+        StringBuilder sb = new StringBuilder();
+        for (Map.Entry<String, String> entry : map.entrySet()){
+            String path = entry.getKey();
+            String controller = entry.getValue();
+
+            sb.append(path).append(controller).append('\n');
+        }
+        return sb.toString();
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part3/Bird.java b/src/main/java/com/zipcodewilmington/assessment2/part3/Bird.java
index ee230c5..14101cb 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part3/Bird.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part3/Bird.java
@@ -1,8 +1,9 @@
 package com.zipcodewilmington.assessment2.part3;
 
-public class Bird {
+public abstract class Bird implements Animal{
+
     public String move() {
-        return null;
+        return "fly";
     }
 
     public void setMigrationMonth(String expected) {
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part3/BlueJay.java b/src/main/java/com/zipcodewilmington/assessment2/part3/BlueJay.java
index f18d13a..dd8bcbe 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part3/BlueJay.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part3/BlueJay.java
@@ -1,4 +1,14 @@
 package com.zipcodewilmington.assessment2.part3;
 
-public class BlueJay {
+public class BlueJay extends Bird{
+
+    @Override
+    public int getSpeed() {
+        return 13;
+    }
+
+    @Override
+    public String color() {
+        return "blue";
+    }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part3/Horse.java b/src/main/java/com/zipcodewilmington/assessment2/part3/Horse.java
index e78cf2b..e033c1c 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part3/Horse.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part3/Horse.java
@@ -1,4 +1,18 @@
 package com.zipcodewilmington.assessment2.part3;
 
-public class Horse{
+public class Horse implements Animal{
+    @Override
+    public String move() {
+        return "gallop";
+    }
+
+    @Override
+    public int getSpeed() {
+        return 40;
+    }
+
+    @Override
+    public String color() {
+        return "brown";
+    }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part3/RedRobin.java b/src/main/java/com/zipcodewilmington/assessment2/part3/RedRobin.java
index c1e85f2..804a1b3 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part3/RedRobin.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part3/RedRobin.java
@@ -1,4 +1,20 @@
 package com.zipcodewilmington.assessment2.part3;
 
-public class RedRobin {
+public class RedRobin extends Bird{
+
+    String migrationMonth;
+
+    @Override
+    public int getSpeed() {
+        return 10;
+    }
+
+    @Override
+    public String color() {
+        return "red";
+    }
+
+    public String getMigrationMonth() { return this.migrationMonth; }
+
+    public void setMigrationMonth(String migrationMonth) { this.migrationMonth = migrationMonth; }
 }
diff --git a/src/main/java/com/zipcodewilmington/assessment2/part3/SpeedComparator.java b/src/main/java/com/zipcodewilmington/assessment2/part3/SpeedComparator.java
index 532e766..21ed3a2 100644
--- a/src/main/java/com/zipcodewilmington/assessment2/part3/SpeedComparator.java
+++ b/src/main/java/com/zipcodewilmington/assessment2/part3/SpeedComparator.java
@@ -1,4 +1,12 @@
 package com.zipcodewilmington.assessment2.part3;
 
-public class SpeedComparator {
+import java.util.Comparator;
+
+public class SpeedComparator implements Comparator<Animal> {
+    @Override
+    public int compare(Animal animal1, Animal animal2) {
+        if (animal1.getSpeed() > animal2.getSpeed()) return -1;
+        if (animal1.getSpeed() < animal2.getSpeed()) return 1;
+        return 0;
+    }
 }
diff --git a/src/test/java/com/zipcodewilmington/assessment2/part2/arrayutility/RotateTest.java b/src/test/java/com/zipcodewilmington/assessment2/part2/arrayutility/RotateTest.java
index 523f355..2f08f74 100644
--- a/src/test/java/com/zipcodewilmington/assessment2/part2/arrayutility/RotateTest.java
+++ b/src/test/java/com/zipcodewilmington/assessment2/part2/arrayutility/RotateTest.java
@@ -25,6 +25,7 @@ public void testRotateLeft_forOne(){
 
         //Then
         Assert.assertArrayEquals(expected, actual);
+        System.out.println(actual);
     }
 
     @Test
diff --git a/src/test/java/com/zipcodewilmington/assessment2/part2/router/ToStringTest.java b/src/test/java/com/zipcodewilmington/assessment2/part2/router/ToStringTest.java
index b199783..e09eb02 100644
--- a/src/test/java/com/zipcodewilmington/assessment2/part2/router/ToStringTest.java
+++ b/src/test/java/com/zipcodewilmington/assessment2/part2/router/ToStringTest.java
@@ -36,7 +36,7 @@ public void test4() {
                 new Pair<>("/instructors", "InstructorController"));
     }
 
-    @Test
+
     public void test(Pair<String, String>... pairs) {
         // given
         StringBuilder expectedString = new StringBuilder();