2.5 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 2.5 of the output value, so we can write it down as x%=2.5.
5. Now we have two simple equations:
1) 100%=81
2) x%=2.5
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%=81/2.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 2.5 is what percent of 81

100%/x%=81/2.5
(100/x)*x=(81/2.5)*x       - we multiply both sides of the equation by x
100=32.4*x       - we divide both sides of the equation by (32.4) to get x
100/32.4=x
3.0864197530864=x
x=3.0864197530864

now we have:
2.5 is 3.0864197530864% of 81