Question

If A={1,2,3,5,7} and B{2,4,6,7}, then find n(AuB)

Answer 1

Step-by-step explanation:

(AUB)={1,2,3,5,7}U{2,4,6,7}

={1,2,3,4,5,6,7}

A∩B={2,7}

n(A∩B)=2

n(AUB)=n(A)+n(B)-n(A∩B)

=5+4-2

=7

For 2 marks....