420.5 is what percent of 421 - 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 421 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 421, so we can write it down as 100%=421.
4. We know, that x% equals 420.5 of the output value, so we can write it down as x%=420.5.
5. Now we have two simple equations:
1) 100%=421
2) x%=420.5
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%=421/420.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 420.5 is what percent of 421

100%/x%=421/420.5
(100/x)*x=(421/420.5)*x       - we multiply both sides of the equation by x
100=1.0011890606421*x       - we divide both sides of the equation by (1.0011890606421) to get x
100/1.0011890606421=x
99.881235154394=x
x=99.881235154394

now we have:
420.5 is 99.881235154394% of 421