19.8 is what percent of 21.78 - 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 21.78 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 21.78, so we can write it down as 100%=21.78.
4. We know, that x% equals 19.8 of the output value, so we can write it down as x%=19.8.
5. Now we have two simple equations:
1) 100%=21.78
2) x%=19.8
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%=21.78/19.8
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 19.8 is what percent of 21.78

100%/x%=21.78/19.8
(100/x)*x=(21.78/19.8)*x       - we multiply both sides of the equation by x
100=1.1*x       - we divide both sides of the equation by (1.1) to get x
100/1.1=x
90.909090909091=x
x=90.909090909091

now we have:
19.8 is 90.909090909091% of 21.78