9.99 is what percent of 12.4 - 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 12.4 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 12.4, so we can write it down as 100%=12.4.
4. We know, that x% equals 9.99 of the output value, so we can write it down as x%=9.99.
5. Now we have two simple equations:
1) 100%=12.4
2) x%=9.99
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%=12.4/9.99
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 9.99 is what percent of 12.4

100%/x%=12.4/9.99
(100/x)*x=(12.4/9.99)*x       - we multiply both sides of the equation by x
100=1.2412412412412*x       - we divide both sides of the equation by (1.2412412412412) to get x
100/1.2412412412412=x
80.564516129032=x
x=80.564516129032

now we have:
9.99 is 80.564516129032% of 12.4