21 is what percent of 126 - 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 126 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 126, so we can write it down as 100%=126.
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%=126
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%=126/21
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 126

100%/x%=126/21
(100/x)*x=(126/21)*x       - we multiply both sides of the equation by x
100=6*x       - we divide both sides of the equation by (6) to get x
100/6=x
16.6666666667=x
x=16.6666666667

now we have:
21 is 16.6666666667% of 126