6.21 is what percent of 13.8 - 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 13.8 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 13.8, so we can write it down as 100%=13.8.
4. We know, that x% equals 6.21 of the output value, so we can write it down as x%=6.21.
5. Now we have two simple equations:
1) 100%=13.8
2) x%=6.21
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%=13.8/6.21
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 6.21 is what percent of 13.8

100%/x%=13.8/6.21
(100/x)*x=(13.8/6.21)*x       - we multiply both sides of the equation by x
100=2.2222222222222*x       - we divide both sides of the equation by (2.2222222222222) to get x
100/2.2222222222222=x
45=x
x=45

now we have:
6.21 is 45% of 13.8