10 friends meet for movie 20 for picnic and 5 for games 4 for movie & picnic 2 for movie & games, 0 for picnic & games, 2 for all, how many are students are there in all?
Select the correct option:
A) 30  B) 31  C) 32  D) 33  E) 34

Rationale: n ( a u b u c ) = n ( a ) + n ( b ) + n ( c ) - n ( a intersection b ) - n ( a intersection c ) - n ( c intersection b ) + n ( a intersection b - intersection c ) hence , total no . of students = 10 + 20 + 5 - 4 - 0 - 2 + 2 = 31 . answer : b
Answer: B