31.4 is what percent of 81 - 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 81 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 81, so we can write it down as 100%=81.
4. We know, that x% equals 31.4 of the output value, so we can write it down as x%=31.4.
5. Now we have two simple equations:
1) 100%=81
2) x%=31.4
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%=81/31.4
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 31.4 is what percent of 81

100%/x%=81/31.4
(100/x)*x=(81/31.4)*x       - we multiply both sides of the equation by x
100=2.5796178343949*x       - we divide both sides of the equation by (2.5796178343949) to get x
100/2.5796178343949=x
38.765432098765=x
x=38.765432098765

now we have:
31.4 is 38.765432098765% of 81