20 is what percent of 3.91 - 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 3.91 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 3.91, so we can write it down as 100%=3.91.
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%=3.91
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%=3.91/20
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 3.91

100%/x%=3.91/20
(100/x)*x=(3.91/20)*x       - we multiply both sides of the equation by x
100=0.1955*x       - we divide both sides of the equation by (0.1955) to get x
100/0.1955=x
511.50895140665=x
x=511.50895140665

now we have:
20 is 511.50895140665% of 3.91