90 is what percent of 13 - 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 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, so we can write it down as 100%=13.
4. We know, that x% equals 90 of the output value, so we can write it down as x%=90.
5. Now we have two simple equations:
1) 100%=13
2) x%=90
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%=13/90
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 90 is what percent of 13

100%/x%=13/90
(100/x)*x=(13/90)*x       - we multiply both sides of the equation by x
100=0.14444444444444*x       - we divide both sides of the equation by (0.14444444444444) to get x
100/0.14444444444444=x
692.30769230769=x
x=692.30769230769

now we have:
90 is 692.30769230769% of 13