In a class of 38 children,19 play tennis, 21 play squash and 10 play neither sport. (1)how many children play both sports?  Choose the correct choice.
A) 11 B) 12 C) 14 D) 15 E) 19

Rationale: 28 play some sport 19 + 21 - both = 28 both = 12 answer is b
Answer: B