21 is what percent of 74.2 - 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 74.2 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 74.2, so we can write it down as 100%=74.2.
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%=74.2
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%=74.2/21
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 74.2

100%/x%=74.2/21
(100/x)*x=(74.2/21)*x       - we multiply both sides of the equation by x
100=3.5333333333333*x       - we divide both sides of the equation by (3.5333333333333) to get x
100/3.5333333333333=x
28.301886792453=x
x=28.301886792453

now we have:
21 is 28.301886792453% of 74.2