21 is what percent of 1286 - 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 1286 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 1286, so we can write it down as 100%=1286.
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%=1286
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%=1286/21
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 1286

100%/x%=1286/21
(100/x)*x=(1286/21)*x       - we multiply both sides of the equation by x
100=61.238095238095*x       - we divide both sides of the equation by (61.238095238095) to get x
100/61.238095238095=x
1.6329704510109=x
x=1.6329704510109

now we have:
21 is 1.6329704510109% of 1286