What is 12.9 percent of 31.1 - 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 31.1 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 31.1 is 100%, so we can write it down as 31.1=100%.
4. We know, that x is 12.9% of the output value, so we can write it down as x=12.9%.
5. Now we have two simple equations:
1) 31.1=100%
2) x=12.9%
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:
31.1/x=100%/12.9%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 12.9% of 31.1

31.1/x=100/12.9
(31.1/x)*x=(100/12.9)*x       - we multiply both sides of the equation by x
31.1=7.7519379845*x       - we divide both sides of the equation by (7.7519379845) to get x
31.1/7.7519379845=x
4.0119=x
x=4.0119

now we have:
12.9% of 31.1=4.0119