Question

If $A=\{x|x\in N,x\le 5\},B=\{x|x\in Z,x^2-5x+6=0\}$, then the number of onto functions from A to B is

• A. 30
• B. 2
• C. 32
• D. 23

Answer 1

Answer: (A)

$A=\left\{1,2,3,4,5\right\}$
$B=\left\{2,3\right\}$
number of onto functions from a set to a set containing 2 elements is
$=2^n-2$
$=2^5-2=30$