Question

If A = {3, 5, 7, 9, 11} and B = {4, 7, 10}, find: A ∩ B and n(A ∩ B)

Answer 1

Find A ∩ B

The intersection of two sets A and B is the set of elements that are common to both. Comparing the elements of A and B:

Common element: 7

Thus: A ∩ B = {7}

Find n(A ∩ B)

n(A ∩ B) = 1.

A ∩ B = {7}

n(A ∩ B) = 1