Q29Multiple choice
Suppose A1, A2, ..., A30 are thirty sets each having 5 elements and B1, B2, ..., Bn 30 n are n sets each with 3 elements, let ∪ Ai = ∪ B j = S and each element of S i =1 j =1 belongs to exactly 10 of the Ai’s and exactly 9 of the B,’S. then n is equal to
- (A)15
- (B)3
- (C)45
- (D)35