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..b45a48448 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 +10,12 @@ public class Lesson11 {
    * https://leetcode.com/problems/concatenation-of-array
    */
   public int[] getConcatenation(int[] nums) {
-    return null;
+    int answer[] = new int[nums.length * 2];
+    for (int i = 0; i < nums.length; i++) {
+      answer[i] = nums[i];
+      answer[i + nums.length] = nums[i];
+    }
+    return answer;
   }
 
   /**
@@ -17,6 +23,13 @@ public int[] getConcatenation(int[] nums) {
    * https://leetcode.com/problems/find-words-containing-character/
    */
   public List<Integer> findWordsContaining(String[] words, char x) {
-    return null;
+    var result = new ArrayList<Integer>();
+    for (int i = 0; i < words.length; i++) {
+      if (words[i].indexOf(x) != -1) {
+        result.add(i);
+      }
+    }
+
+    return result;
   }
 }
diff --git a/lesson_11/arrays_ts/src/lesson11.ts b/lesson_11/arrays_ts/src/lesson11.ts
index 54af1ba03..c50ac5d39 100644
--- a/lesson_11/arrays_ts/src/lesson11.ts
+++ b/lesson_11/arrays_ts/src/lesson11.ts
@@ -3,7 +3,12 @@
  * https://leetcode.com/problems/concatenation-of-array
  */
 export function getConcatenation(nums: number[]): number[] {
-  return [];
+  if (nums.length === 0) return [];
+  const result = [...nums];
+  for (const num of nums) {
+    result.push(num);
+  }
+  return result;
 }
 
 /**
@@ -11,5 +16,12 @@ export function getConcatenation(nums: number[]): number[] {
  * https://leetcode.com/problems/find-words-containing-character/
  */
 export function findWordsContaining(words: string[], x: string): number[] {
-  return [];
+  if (words.length === 0) return [];
+  const result = [];
+  for (let i = 0; i < words.length; i++) {
+    if (words[i].includes(x)) {
+      result.push(i);
+    }
+  }
+  return result;
 }