20 is what percent of 27.81 - 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 27.81 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 27.81, so we can write it down as 100%=27.81.
4. We know, that x% equals 20 of the output value, so we can write it down as x%=20.
5. Now we have two simple equations:
1) 100%=27.81
2) x%=20
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%=27.81/20
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 20 is what percent of 27.81

100%/x%=27.81/20
(100/x)*x=(27.81/20)*x       - we multiply both sides of the equation by x
100=1.3905*x       - we divide both sides of the equation by (1.3905) to get x
100/1.3905=x
71.916576770946=x
x=71.916576770946

now we have:
20 is 71.916576770946% of 27.81