Question

Which of the following two sets are disjoint?
{1,3,5}&{1,3,6}, {1,2,3}&{1,2,3}, {1,3,5}&{2,3,4}, or
{1,3,5}&{2,4,6}.​

Answer 1

{1,3,5} and {2,4,6} are disjoint because they have no common element.