28 is what percent of 217 - 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 217 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 217, so we can write it down as 100%=217.
4. We know, that x% equals 28 of the output value, so we can write it down as x%=28.
5. Now we have two simple equations:
1) 100%=217
2) x%=28
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%=217/28
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 28 is what percent of 217

100%/x%=217/28
(100/x)*x=(217/28)*x       - we multiply both sides of the equation by x
100=7.75*x       - we divide both sides of the equation by (7.75) to get x
100/7.75=x
12.9032258065=x
x=12.9032258065

now we have:
28 is 12.9032258065% of 217