21 is what percent of 275 - 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 275 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 275, so we can write it down as 100%=275.
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%=275
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%=275/21
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 275

100%/x%=275/21
(100/x)*x=(275/21)*x       - we multiply both sides of the equation by x
100=13.0952380952*x       - we divide both sides of the equation by (13.0952380952) to get x
100/13.0952380952=x
7.63636363636=x
x=7.63636363636

now we have:
21 is 7.63636363636% of 275