12.9 is what percent of 13.9 - 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 13.9 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 13.9, so we can write it down as 100%=13.9.
4. We know, that x% equals 12.9 of the output value, so we can write it down as x%=12.9.
5. Now we have two simple equations:
1) 100%=13.9
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:
100%/x%=13.9/12.9
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 12.9 is what percent of 13.9

100%/x%=13.9/12.9
(100/x)*x=(13.9/12.9)*x       - we multiply both sides of the equation by x
100=1.077519379845*x       - we divide both sides of the equation by (1.077519379845) to get x
100/1.077519379845=x
92.805755395683=x
x=92.805755395683

now we have:
12.9 is 92.805755395683% of 13.9