Question

In a class of 50 boys, 35 boys play Carrom and 20 boys play Chess then the number of boys play both games is 

Options

• 5

• 30

• 15

• 10

Answer 1

5

Explanation;

Hint:

n(A ∪ B) = 50, n(A) = 35, n(B) = 20

n(A ∩ B) = n(A) + n(B) – n(A ∪ B)

= 35 + 20 – 50

= 5