diff --git a/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java b/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
index 248938a96..80c33c27b 100644
--- a/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
+++ b/lesson_11/arrays_java/arrays_app/src/main/java/com/codedifferently/lesson11/Lesson11.java
@@ -1,5 +1,6 @@
 package com.codedifferently.lesson11;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class Lesson11 {
@@ -9,7 +10,13 @@ public class Lesson11 {
    * https://leetcode.com/problems/concatenation-of-array
    */
   public int[] getConcatenation(int[] nums) {
-    return null;
+    int n = nums.length; 
+    int [] ans = new int [n * 2];
+    for (int i=0; i < n; i++){
+      ans [i] = nums[i];
+      ans [i + n] = nums[i];
+    }
+    return ans;
   }
 
   /**
@@ -17,6 +24,13 @@ public int[] getConcatenation(int[] nums) {
    * https://leetcode.com/problems/find-words-containing-character/
    */
   public List<Integer> findWordsContaining(String[] words, char x) {
-    return null;
+    ArrayList <Integer>  result = new ArrayList <>();
+
+    for(int i=0; i< words.length: i++) {
+      if(words [i].indexOf(x) != -1) {
+        result.add(i);
+      } 
+    }
+    return result;
   }
 }