Question

A is a set of all the prime numbers less than 20, B is a set of all the even natural numbers less than 20 and C is a set of all the odd natural numbers. Which of the following is/are true statements ?
(A) `A nn B` is a singleton set.
(B) B and C are disjoint sets.
(C) `A nn C` is an infinite set.
A. Only (B)
B. Both (A) and (B)
C. Both (B) and (C)
D. (A), (B) and (C)

Answer 1

Correct Answer - B
Given that A is a set of all the prime numbers less than `20 implies A={2, 3, 5, 7, 11, 13, 17, 19}`
B is a set of all the even natural numbers less then `20 implies B={2, 4, 6, 8, 10, 12, 14, 16, 18}`
C is a set of all the odd natural numbers `implies C={1, 3, 5, 7 ...}`
(a) `A nn B={2}` is a singleton set.
(b) `B nn C={ }implies B` and `C` are disjoint sets.
(c) `A nn C={3, 5, 7, 11, 13, 17, 19}` is not an infinite set.
Hence, choice (2) follows.
Hence, the correct option is (b).