1/5=2/10=5/25
To get 2/10, since, in the denominators, to go from 5 to 10, you multiply 5 by 2, I multiplied 1 and 2 to get the answer.
For 5/25, to go from 1 to 5 you multiply 1 by 5, so you multiply 5 by 5, and that's 25, so the denominator for that fraction is 25.