643.75 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 643.75 of the output value, so we can write it down as x%=643.75.
5. Now we have two simple equations:
1) 100%=515
2) x%=643.75
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%=515/643.75
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 643.75 is what percent of 515

100%/x%=515/643.75
(100/x)*x=(515/643.75)*x       - we multiply both sides of the equation by x
100=0.8*x       - we divide both sides of the equation by (0.8) to get x
100/0.8=x
125=x
x=125

now we have:
643.75 is 125% of 515