315 is what percent of 402 - 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 402 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 402, so we can write it down as 100%=402.
4. We know, that x% equals 315 of the output value, so we can write it down as x%=315.
5. Now we have two simple equations:
1) 100%=402
2) x%=315
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%=402/315
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 315 is what percent of 402

100%/x%=402/315
(100/x)*x=(402/315)*x       - we multiply both sides of the equation by x
100=1.2761904761905*x       - we divide both sides of the equation by (1.2761904761905) to get x
100/1.2761904761905=x
78.358208955224=x
x=78.358208955224

now we have:
315 is 78.358208955224% of 402