20 is what percent of 87 - 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 87 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 87, so we can write it down as 100%=87.
4. We know, that x% equals 20 of the output value, so we can write it down as x%=20.
5. Now we have two simple equations:
1) 100%=87
2) x%=20
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%=87/20
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 20 is what percent of 87

100%/x%=87/20
(100/x)*x=(87/20)*x       - we multiply both sides of the equation by x
100=4.35*x       - we divide both sides of the equation by (4.35) to get x
100/4.35=x
22.9885057471=x
x=22.9885057471

now we have:
20 is 22.9885057471% of 87