43.5 is what percent of 640 - 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 640 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 640, so we can write it down as 100%=640.
4. We know, that x% equals 43.5 of the output value, so we can write it down as x%=43.5.
5. Now we have two simple equations:
1) 100%=640
2) x%=43.5
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%=640/43.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 43.5 is what percent of 640

100%/x%=640/43.5
(100/x)*x=(640/43.5)*x       - we multiply both sides of the equation by x
100=14.712643678161*x       - we divide both sides of the equation by (14.712643678161) to get x
100/14.712643678161=x
6.796875=x
x=6.796875

now we have:
43.5 is 6.796875% of 640