18 is what percent of 210 - 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 210 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 210, so we can write it down as 100%=210.
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%=210
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%=210/18
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 210

100%/x%=210/18
(100/x)*x=(210/18)*x       - we multiply both sides of the equation by x
100=11.666666666667*x       - we divide both sides of the equation by (11.666666666667) to get x
100/11.666666666667=x
8.5714285714286=x
x=8.5714285714286

now we have:
18 is 8.5714285714286% of 210