Question

if a={1,2,3,4,5,7,9,11},find n(A)​

Answer 1

Answer:

A={2,3,4,5,7}

n(A)=5

B={7,8,9}

n(B)=3

n(A∩B)=1

∴(A∪B)=n(A)+n(B)−n(A∩B)

(A∪B)=5+3−1=7

Step-by-step explanation: