257.5 is what percent of 515 - step by step solution

To get the solution, we are looking for, we need to point out what we know.

1. We assume, that the number 515 is 100% - because it's the output value of the task.
2. We assume, that x is the value we are looking for.
3. If 100% equals 515, so we can write it down as 100%=515.
4. We know, that x% equals 257.5 of the output value, so we can write it down as x%=257.5.
5. Now we have two simple equations:
1) 100%=515
2) x%=257.5
where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:
100%/x%=515/257.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 257.5 is what percent of 515

100%/x%=515/257.5
(100/x)*x=(515/257.5)*x       - we multiply both sides of the equation by x
100=2*x       - we divide both sides of the equation by (2) to get x
100/2=x
50=x
x=50

now we have:
257.5 is 50% of 515