9.99 is what percent of 19.98 - 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 19.98 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 19.98, so we can write it down as 100%=19.98.
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%=19.98
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%=19.98/9.99
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 19.98

100%/x%=19.98/9.99
(100/x)*x=(19.98/9.99)*x       - we multiply both sides of the equation by x
100=2*x       - we divide both sides of the equation by (2) to get x
100/2=x
50=x
x=50

now we have:
9.99 is 50% of 19.98