diff --git a/src/my_project/interviews/top_150_questions_round_12/merge_sorted_array.py b/src/my_project/interviews/top_150_questions_round_12/merge_sorted_array.py
new file mode 100644
index 00000000..34a8d66c
--- /dev/null
+++ b/src/my_project/interviews/top_150_questions_round_12/merge_sorted_array.py
@@ -0,0 +1,14 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def merge(self, 
+              nums1: List[int], 
+              m: int, nums2: List[int], 
+              n: int) -> None:
+        
+        nums1[m: m+n] = nums2
+
+        nums1.sort()
+
+        return nums1
\ No newline at end of file
diff --git a/tests/test_150_questions_round_12/test_merge_sorted_array_round_12.py b/tests/test_150_questions_round_12/test_merge_sorted_array_round_12.py
new file mode 100644
index 00000000..a450edaa
--- /dev/null
+++ b/tests/test_150_questions_round_12/test_merge_sorted_array_round_12.py
@@ -0,0 +1,12 @@
+import unittest
+from src.my_project.interviews.top_150_questions_round_12\
+.merge_sorted_array import Solution
+
+class MergeSortedArrayTestCase(unittest.TestCase):
+
+    def test_merge_sorted_array(self):
+        solution = Solution()
+        output = solution.merge(nums1=[1,2,3,0,0,0], m=3, nums2=[2,5,6], n=3)
+        target = [1,2,2,3,5,6]
+        for k, v in enumerate(target):
+            self.assertEqual(output[k], v)
\ No newline at end of file