15 is what percent of 243 - 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 243 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 243, so we can write it down as 100%=243.
4. We know, that x% equals 15 of the output value, so we can write it down as x%=15.
5. Now we have two simple equations:
1) 100%=243
2) x%=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:
100%/x%=243/15
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 15 is what percent of 243

100%/x%=243/15
(100/x)*x=(243/15)*x       - we multiply both sides of the equation by x
100=16.2*x       - we divide both sides of the equation by (16.2) to get x
100/16.2=x
6.1728395061728=x
x=6.1728395061728

now we have:
15 is 6.1728395061728% of 243