0.81 is what percent of 15.99 - 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 15.99 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 15.99, so we can write it down as 100%=15.99.
4. We know, that x% equals 0.81 of the output value, so we can write it down as x%=0.81.
5. Now we have two simple equations:
1) 100%=15.99
2) x%=0.81
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%=15.99/0.81
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 0.81 is what percent of 15.99

100%/x%=15.99/0.81
(100/x)*x=(15.99/0.81)*x       - we multiply both sides of the equation by x
100=19.740740740741*x       - we divide both sides of the equation by (19.740740740741) to get x
100/19.740740740741=x
5.0656660412758=x
x=5.0656660412758

now we have:
0.81 is 5.0656660412758% of 15.99