Question

Let U = {5, 10, 15, 20, 25, 30, 35, 40}

A = {5, 10, 15, 20}

B = {25, 30, 35, 40}

C = {10, 20, 30, 40}.

Find A ⋂ C.

Answer 1

A∩C is a set all elements of which are present in A <i>and</i> present in C.

For example, if P={1,2,3,4,5} and Q={1,3,5}, then P∩Q={1,3,5} since 1, 3 and 5 are elements of both P and Q.

In the question posted, A∩C should have two elements.