In a group of 500 people, 350 are engineers and 250 are MBAs.
How many are both Engineers and MBAs?
As, we know {A ∪ B} = A + B - (A ∩ B)
A ∪ B = 500 , A = 250 and B = 350
500 = 250 + 350 - (A ∩ B)
(A ∩ B) = 100
100 are both Engineers and MBAs.
Hence option (a)