How many three-digit numbers can you make up of odd digits?

There are five odd numbers that we can use to write a number. To find out how many three-digit numbers can be composed of odd digits, you need to raise the number of digits to a power equal to the number of digits in the numbers. That is, 5 to 3 third degree. It turns out 125.

Provided that the numbers are not repeated (each number occurs exactly once in the number), then
We have 5 odd digits – these are 1, 3, 5, 7, 9.
The first digit can be one of 5.
The second is one of the 4 remaining.
The third is out of 3.
This means 5 * 4 * 3 = 60.