21 is what percent of 285.5 - 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 285.5 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 285.5, so we can write it down as 100%=285.5.
4. We know, that x% equals 21 of the output value, so we can write it down as x%=21.
5. Now we have two simple equations:
1) 100%=285.5
2) x%=21
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%=285.5/21
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 21 is what percent of 285.5

100%/x%=285.5/21
(100/x)*x=(285.5/21)*x       - we multiply both sides of the equation by x
100=13.595238095238*x       - we divide both sides of the equation by (13.595238095238) to get x
100/13.595238095238=x
7.3555166374781=x
x=7.3555166374781

now we have:
21 is 7.3555166374781% of 285.5