90 is what percent of 3105 - 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 3105 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 3105, so we can write it down as 100%=3105.
4. We know, that x% equals 90 of the output value, so we can write it down as x%=90.
5. Now we have two simple equations:
1) 100%=3105
2) x%=90
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%=3105/90
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 90 is what percent of 3105

100%/x%=3105/90
(100/x)*x=(3105/90)*x       - we multiply both sides of the equation by x
100=34.5*x       - we divide both sides of the equation by (34.5) to get x
100/34.5=x
2.8985507246377=x
x=2.8985507246377

now we have:
90 is 2.8985507246377% of 3105