Solution

154949

First name
Mohamed Ali
School
King Solomon Academy
Country
Age
11

I first tried trial and error but I realised that it would take too long. So I just simply put the opposite number on each side. That didn't work so I adjusted it a bit and I finally got the answer:

n=8

8 ¦ 13 ¦ 12
--------------
15 ¦ 11 ¦ 7
---------------
10 ¦ 9 ¦ 14