Question

Let $A$ and $B$ be two sets containing four and two elements respectively. Then the number of subsets of the set $A \times B$, each having at least three elements is :

• A. 219
• B. 256
• C. 275
• D. 510

Answer 1

Answer: (A)

219

Answer 2

$n(A \times B)=8$
Total subsets $=2^{8}$
${ }^{8} C _{0}+8 C _{1}+{ }^{8} C _{2}$
$=37$
No. of Re Subsets $=256-37$
$=219$.