Question

The number 75 can be written as the sum of the squares of 3 different positive integers. what is the sum of these 3 integers?

Answer 1

the square numbers smaller than 75 are 1, 4, 9, 16, 25, 36, 49, 64
1+49+25=75 seems to be the only set possible. 
1+7+5=13
the answer is 13