0.9 is what percent of 21.1 - 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 21.1 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 21.1, so we can write it down as 100%=21.1.
4. We know, that x% equals 0.9 of the output value, so we can write it down as x%=0.9.
5. Now we have two simple equations:
1) 100%=21.1
2) x%=0.9
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%=21.1/0.9
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 0.9 is what percent of 21.1

100%/x%=21.1/0.9
(100/x)*x=(21.1/0.9)*x       - we multiply both sides of the equation by x
100=23.444444444444*x       - we divide both sides of the equation by (23.444444444444) to get x
100/23.444444444444=x
4.2654028436019=x
x=4.2654028436019

now we have:
0.9 is 4.2654028436019% of 21.1