21 is what percent of 605 - 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 605 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 605, so we can write it down as 100%=605.
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%=605
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%=605/21
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 605

100%/x%=605/21
(100/x)*x=(605/21)*x       - we multiply both sides of the equation by x
100=28.8095238095*x       - we divide both sides of the equation by (28.8095238095) to get x
100/28.8095238095=x
3.47107438017=x
x=3.47107438017

now we have:
21 is 3.47107438017% of 605