77.55 is what percent of 390 - 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 390 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 390, so we can write it down as 100%=390.
4. We know, that x% equals 77.55 of the output value, so we can write it down as x%=77.55.
5. Now we have two simple equations:
1) 100%=390
2) x%=77.55
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%=390/77.55
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 77.55 is what percent of 390

100%/x%=390/77.55
(100/x)*x=(390/77.55)*x       - we multiply both sides of the equation by x
100=5.0290135396518*x       - we divide both sides of the equation by (5.0290135396518) to get x
100/5.0290135396518=x
19.884615384615=x
x=19.884615384615

now we have:
77.55 is 19.884615384615% of 390