25 persons are in a room 15 of them play hockey, 17 of them play football and 10 of them play hockey and football. Then the number of persons playing neither hockey nor football is (A) 2 (B) 17 (C) 13 (D) 3
The answer will be three (D)
Thsi can be calculated bet using
P(AUB)=P(A)+P(B)-P(A intersection B)
which will give the answer as 3