9 is what percent of 121.5 - 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 121.5 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 121.5, so we can write it down as 100%=121.5.
4. We know, that x% equals 9 of the output value, so we can write it down as x%=9.
5. Now we have two simple equations:
1) 100%=121.5
2) x%=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%=121.5/9
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 9 is what percent of 121.5

100%/x%=121.5/9
(100/x)*x=(121.5/9)*x       - we multiply both sides of the equation by x
100=13.5*x       - we divide both sides of the equation by (13.5) to get x
100/13.5=x
7.4074074074074=x
x=7.4074074074074

now we have:
9 is 7.4074074074074% of 121.5