Question

If $A=\{2,4,5\},B=\{7,8,9\}$, then $n(A\times B)$ is equal to

• A. 6
• B. 9
• C. 3
• D. 0

Answer 1

Answer: (B)

$n(A\times B)=n(A).n(B)=3\times 3=9$