Question

How many $4$ digit number can be formed with a digits $1,2,3,4$ which are divisible by $4$

Answer 1

No. is divisible by $4$ if last two digit is divisible by $4$.

So, from given two last two digit should be $12$ or $24$

Case (i)

No. of $4$ digit are $=2\times 1\times 1\times 1$

$=2$

Case (ii)

$\therefore$No. of $4$ digit no. $=2$

$\therefore$ Total $4$ digit no.$=2+2$

$=4$.