What is 91 percent of 13.8 - 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 13.8 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 13.8 is 100%, so we can write it down as 13.8=100%.
4. We know, that x is 91% of the output value, so we can write it down as x=91%.
5. Now we have two simple equations:
1) 13.8=100%
2) x=91%
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:
13.8/x=100%/91%
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 91% of 13.8

13.8/x=100/91
(13.8/x)*x=(100/91)*x       - we multiply both sides of the equation by x
13.8=1.0989010989011*x       - we divide both sides of the equation by (1.0989010989011) to get x
13.8/1.0989010989011=x
12.558=x
x=12.558

now we have:
91% of 13.8=12.558