A four digit number is formed using the digits `1, 2, 3, 5` with no repetitions. Write the probability that the number is divisible by `5`.

Explanation

Total number of ways - Four-digit numbers formed `=4! =24`.


A number is divisible by `5` if unit's place `=5`.


Unit's place can be filled in `1` way and the remaining `3` places can be filled with `1, 2, 3` in `3!` ways.


Total number of four digits number divisible by `5` is `=3! =6`.


Required probability `=6/24=1/4`.