Question

Let A = {15, 25, 35, 45, 55, 65} and B = {25, 45, 65}. What is A ∩ B?

Answer 1

A∩B={
`25, 45, 65`}

B is a proper subset of A:

B⊂A

Explanation:

A∩B means the intersection of the set A and the set B. In other words, is the set of elements contained in these both sets.

Given the set A and the set B:

`A =`{
`15, 25, 35, 45, 55, 65`}

`B =`{
`25, 45, 65`}

You can indentify that the numbers common in both sets are: 25,45 and 65.

Therefore you get:

A∩B={
`25, 45, 65`}

Since all elements of B are in A, and A contains elements that are not in B, then B is a proper subset of A:

B⊂A