There are three numbers less then four (1, 2, and 3) and two multiples of nine (9 and 18) from 1-25. That would make the fraction 5/25 before simplifying to 1/5.
There are 3 numbers of less than 4 (1, 2 and 3) and there are 2 multiples of 9 (9 and 18). So there are 5 favourable outcomes and 25 possible outcomes. So you put 5/25 and cancel down, which makes 1/5. I hope this helps!
