21 is what percent of 3.69 - 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 3.69 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 3.69, so we can write it down as 100%=3.69.
4. We know, that x% equals 21 of the output value, so we can write it down as x%=21.
5. Now we have two simple equations:
1) 100%=3.69
2) x%=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%=3.69/21
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 21 is what percent of 3.69

100%/x%=3.69/21
(100/x)*x=(3.69/21)*x       - we multiply both sides of the equation by x
100=0.17571428571429*x       - we divide both sides of the equation by (0.17571428571429) to get x
100/0.17571428571429=x
569.10569105691=x
x=569.10569105691

now we have:
21 is 569.10569105691% of 3.69