Update Day 4.md

Another solution for Question 15

Author: apenam7

Status/Day 4.md

@@ -179,6 +179,11 @@ inp = input()
 print(question_15(inp))
 ```
 ---
+```python
+'''Solution by: apenam7
+'''
+a = input()
+print(sum(int(i*a) for i in range(1,5)))
 
 [**_go to previous day_**](https://github.com/darkprinx/100-plus-Python-programming-exercises-extended/blob/master/Status/Day%203.md "Day 3")