399.75 is what percent of 999 - 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 999 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 999, so we can write it down as 100%=999.
4. We know, that x% equals 399.75 of the output value, so we can write it down as x%=399.75.
5. Now we have two simple equations:
1) 100%=999
2) x%=399.75
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%=999/399.75
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 399.75 is what percent of 999

100%/x%=999/399.75
(100/x)*x=(999/399.75)*x       - we multiply both sides of the equation by x
100=2.4990619136961*x       - we divide both sides of the equation by (2.4990619136961) to get x
100/2.4990619136961=x
40.015015015015=x
x=40.015015015015

now we have:
399.75 is 40.015015015015% of 999