39.9 is what percent of 55 - 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 55 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 55, so we can write it down as 100%=55.
4. We know, that x% equals 39.9 of the output value, so we can write it down as x%=39.9.
5. Now we have two simple equations:
1) 100%=55
2) x%=39.9
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%=55/39.9
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 39.9 is what percent of 55

100%/x%=55/39.9
(100/x)*x=(55/39.9)*x       - we multiply both sides of the equation by x
100=1.3784461152882*x       - we divide both sides of the equation by (1.3784461152882) to get x
100/1.3784461152882=x
72.545454545455=x
x=72.545454545455

now we have:
39.9 is 72.545454545455% of 55