What is 30 percent of 21.09 - 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 21.09 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 21.09 is 100%, so we can write it down as 21.09=100%.
4. We know, that x is 30% of the output value, so we can write it down as x=30%.
5. Now we have two simple equations:
1) 21.09=100%
2) x=30%
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:
21.09/x=100%/30%
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 30% of 21.09

21.09/x=100/30
(21.09/x)*x=(100/30)*x       - we multiply both sides of the equation by x
21.09=3.3333333333333*x       - we divide both sides of the equation by (3.3333333333333) to get x
21.09/3.3333333333333=x
6.327=x
x=6.327

now we have:
30% of 21.09=6.327