21 is what percent of 158.6 - 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 158.6 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 158.6, so we can write it down as 100%=158.6.
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%=158.6
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%=158.6/21
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 158.6

100%/x%=158.6/21
(100/x)*x=(158.6/21)*x       - we multiply both sides of the equation by x
100=7.552380952381*x       - we divide both sides of the equation by (7.552380952381) to get x
100/7.552380952381=x
13.240857503153=x
x=13.240857503153

now we have:
21 is 13.240857503153% of 158.6