200 pupil total,out of 125 like pizza,115 like burger, then how many like both? Choose the correct choice from the following answers.
A) 40 B) 50 C) 60 D) 70 E) 80

Rationale: n ( a u b ) = n ( a ) + n ( b ) - n ( a intersection b ) 200 = 125 + 115 - both both = 240 - 200 = 40 . answer : a
Answer: A