What is 21.15 percent of 18 - 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 18 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 18 is 100%, so we can write it down as 18=100%.
4. We know, that x is 21.15% of the output value, so we can write it down as x=21.15%.
5. Now we have two simple equations:
1) 18=100%
2) x=21.15%
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:
18/x=100%/21.15%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 21.15% of 18

18/x=100/21.15
(18/x)*x=(100/21.15)*x       - we multiply both sides of the equation by x
18=4.7281323877069*x       - we divide both sides of the equation by (4.7281323877069) to get x
18/4.7281323877069=x
3.807=x
x=3.807

now we have:
21.15% of 18=3.807