Question

Let A(1), A(2), A(3),…….., A(100) be 100 sets such that number of elements in A(i)=i+1 and A(1) is subset of A(2), A(2)is subset of A(3),….., A(99) is subset of A(100). The number of elements in union of the all the sets are: n(A(1) U A(2) U A(3) …..U A(100)).

(a) 99

(b) 100

(c) 101

(d) 102

The question was asked by my college director while I was bunking the class.

My doubt stems from Subsets in division Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

Correct answer is (c) 101

Explanation: Since all sets are subsets of A(100) therefore in union only elements of A(100)will come.A(100) contains 101 elements.