Before jumping into doing this problem, it is important to look at all the information's that have been made available in the question. Based on those given conditions the answer to the problem can be easily deduced.
Let us assume the number of friends Sumalee has = x
Then
2x + 8 = 40
2x = 40 -8
2x = 32
x = 32/2
x = 16
So Sumalee has 16 friends. There are numerous ways to get to the answer that is required to be found. This is the easiest and the shortest method. Hope i helped you.
