Question

Which of the following sets are equal?

(a) {a, b, c, d} and {d, c, b, a}

(b) {4,8,12,16} and {8,12,16,18}

(c) {x : x is a multiple of 10} and {10,20,30}

(d) {2,4,6,8} and {x : x is an even number}

This question was addressed to me during an interview.

This question is from Equal Sets in chapter Sets of Mathematics – Class 11

Answer 1

Right answer is (a) {a, b, c, d} and {d, c, b, a}

To elaborate: {a, b, c, d} and {d, c, b, a} are equal sets.

{4,8,12,16} and {8,12,16,18} are not equal their elements are not matching.

{x : x is a multiple of 10} = {10,20,30,………} which is infinite set and not equal to {10,20,30}.

{x : x is an even number} = {2,4,6,………….} which is an infinite set and not equal to {2,4,6}.