21.5 is what percent of 39.5 - 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 39.5 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 39.5, so we can write it down as 100%=39.5.
4. We know, that x% equals 21.5 of the output value, so we can write it down as x%=21.5.
5. Now we have two simple equations:
1) 100%=39.5
2) x%=21.5
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%=39.5/21.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 21.5 is what percent of 39.5

100%/x%=39.5/21.5
(100/x)*x=(39.5/21.5)*x       - we multiply both sides of the equation by x
100=1.8372093023256*x       - we divide both sides of the equation by (1.8372093023256) to get x
100/1.8372093023256=x
54.430379746835=x
x=54.430379746835

now we have:
21.5 is 54.430379746835% of 39.5