Question

If 15 is 25% of a value what is the value

Answer 1

25%=25/100=1/4
x=is that value
1/4 of x=15
We have to solve the following equation:

x(1/4)=15
x/4=15
x=15*4
x=60

Answer: 60 is the value. 

Answer 2

25% is $\frac{1}{4}$ of a number. So, if you'd like to hit the easy way to doing things, you could multiply 15 by 4, and get 60.

And on checking it again, you would find that 15 is indeed 25% of 60. So 60 is the value.