18 is what percent of 220 - 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 220 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 220, so we can write it down as 100%=220.
4. We know, that x% equals 18 of the output value, so we can write it down as x%=18.
5. Now we have two simple equations:
1) 100%=220
2) x%=18
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%=220/18
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 18 is what percent of 220

100%/x%=220/18
(100/x)*x=(220/18)*x       - we multiply both sides of the equation by x
100=12.222222222222*x       - we divide both sides of the equation by (12.222222222222) to get x
100/12.222222222222=x
8.1818181818182=x
x=8.1818181818182

now we have:
18 is 8.1818181818182% of 220