What is 77.5 percent of 20.4 - 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 20.4 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 20.4 is 100%, so we can write it down as 20.4=100%.
4. We know, that x is 77.5% of the output value, so we can write it down as x=77.5%.
5. Now we have two simple equations:
1) 20.4=100%
2) x=77.5%
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:
20.4/x=100%/77.5%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 77.5% of 20.4

20.4/x=100/77.5
(20.4/x)*x=(100/77.5)*x       - we multiply both sides of the equation by x
20.4=1.2903225806452*x       - we divide both sides of the equation by (1.2903225806452) to get x
20.4/1.2903225806452=x
15.81=x
x=15.81

now we have:
77.5% of 20.4=15.81