15.8 is what percent of 30.9 - 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 30.9 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 30.9, so we can write it down as 100%=30.9.
4. We know, that x% equals 15.8 of the output value, so we can write it down as x%=15.8.
5. Now we have two simple equations:
1) 100%=30.9
2) x%=15.8
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%=30.9/15.8
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 15.8 is what percent of 30.9

100%/x%=30.9/15.8
(100/x)*x=(30.9/15.8)*x       - we multiply both sides of the equation by x
100=1.9556962025316*x       - we divide both sides of the equation by (1.9556962025316) to get x
100/1.9556962025316=x
51.132686084142=x
x=51.132686084142

now we have:
15.8 is 51.132686084142% of 30.9