21 is what percent of 70.85 - 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 70.85 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 70.85, so we can write it down as 100%=70.85.
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%=70.85
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%=70.85/21
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 70.85

100%/x%=70.85/21
(100/x)*x=(70.85/21)*x       - we multiply both sides of the equation by x
100=3.3738095238095*x       - we divide both sides of the equation by (3.3738095238095) to get x
100/3.3738095238095=x
29.640084685956=x
x=29.640084685956

now we have:
21 is 29.640084685956% of 70.85