77.9 is what percent of 20.5 - 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 20.5 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 20.5, so we can write it down as 100%=20.5.
4. We know, that x% equals 77.9 of the output value, so we can write it down as x%=77.9.
5. Now we have two simple equations:
1) 100%=20.5
2) x%=77.9
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%=20.5/77.9
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 77.9 is what percent of 20.5

100%/x%=20.5/77.9
(100/x)*x=(20.5/77.9)*x       - we multiply both sides of the equation by x
100=0.26315789473684*x       - we divide both sides of the equation by (0.26315789473684) to get x
100/0.26315789473684=x
380=x
x=380

now we have:
77.9 is 380% of 20.5