78 is what percent of 991 - 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 991 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 991, so we can write it down as 100%=991.
4. We know, that x% equals 78 of the output value, so we can write it down as x%=78.
5. Now we have two simple equations:
1) 100%=991
2) x%=78
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%=991/78
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 78 is what percent of 991

100%/x%=991/78
(100/x)*x=(991/78)*x       - we multiply both sides of the equation by x
100=12.705128205128*x       - we divide both sides of the equation by (12.705128205128) to get x
100/12.705128205128=x
7.8708375378406=x
x=7.8708375378406

now we have:
78 is 7.8708375378406% of 991