91 is what percent of 638 - 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 638 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 638, so we can write it down as 100%=638.
4. We know, that x% equals 91 of the output value, so we can write it down as x%=91.
5. Now we have two simple equations:
1) 100%=638
2) x%=91
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%=638/91
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 91 is what percent of 638

100%/x%=638/91
(100/x)*x=(638/91)*x       - we multiply both sides of the equation by x
100=7.010989010989*x       - we divide both sides of the equation by (7.010989010989) to get x
100/7.010989010989=x
14.263322884013=x
x=14.263322884013

now we have:
91 is 14.263322884013% of 638