Question

If $A$ is the set of even natural numbers less than $\text{8}$ and $B$ is the set of prime numbers less than $\text{7}$ , then the number of relations from $A$ to $B$ are

• A. $2^9$
• B. $9^2$
• C. $3^2$
• D. $2^{9-1}$

Answer 1

Answer: (A)

$A=\{2,4,6\}$ ; $B=\left\{2,3,5\right\}$
$\therefore$ $A\times B$ contains $3\times 3=9$ elements.
Hence, the number of relations from $A$ to $B=2^9$ .