77 is what percent of 399 - 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 399 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 399, so we can write it down as 100%=399.
4. We know, that x% equals 77 of the output value, so we can write it down as x%=77.
5. Now we have two simple equations:
1) 100%=399
2) x%=77
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%=399/77
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 77 is what percent of 399

100%/x%=399/77
(100/x)*x=(399/77)*x       - we multiply both sides of the equation by x
100=5.1818181818182*x       - we divide both sides of the equation by (5.1818181818182) to get x
100/5.1818181818182=x
19.298245614035=x
x=19.298245614035

now we have:
77 is 19.298245614035% of 399