There are 195 chocolates, along with the contribution of each friend that is equal to the number of friends. The total number of chocolates, when divided equally among them, averages to 28. Find the number of friends.

Hi
Let number of friends be n
Now the question says there are 195 chocolates along with contribution of each friend that is equal to number of friends .
So if number of friends are n and so each friend will contribute n chocolates so total contribution will become n^2
Now therefore total chocolates will become : 195+n^2
Now it says when divided equally , the chocolates becomes 28
so we get (n^2+195)/n =28
n^2+195=28n
n^2-28n+195=0
(n-15)(n-13)=0
n=15 or 13.
So number of friends can be 13 or 15.