In a group of 22 boys, 13 play basketball and 15 play football. 3 of the boys play neither. how many play both ?
Pick:
A) 18
B) 20
C) 21
D) 22
E) 25

Rationale: 18 boys play something . if b play both , then 13 + 15 - b = 18 answer is a
Answer: A