Question

What is the probability that a number formed form the digits $1,2,3,4$ would be divisible by $4,$ without repeating the digits?

Answer 1

There are possible numbers that can be formed using $1,2,3,4$ with out repetitions.

$3!=3\times 2\times 1=6$

Also, there are only $2$ possible numbers that divisible by $4$

$2!=2\times 1=2$

Thus,

The required answer is $\frac{3!}{2!}=\frac{2}{6}=\frac{1}{3}$.

Hence, this is the answer.