15.78 is what percent of 18 - 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 18 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 18, so we can write it down as 100%=18.
4. We know, that x% equals 15.78 of the output value, so we can write it down as x%=15.78.
5. Now we have two simple equations:
1) 100%=18
2) x%=15.78
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%=18/15.78
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 15.78 is what percent of 18

100%/x%=18/15.78
(100/x)*x=(18/15.78)*x       - we multiply both sides of the equation by x
100=1.1406844106464*x       - we divide both sides of the equation by (1.1406844106464) to get x
100/1.1406844106464=x
87.666666666667=x
x=87.666666666667

now we have:
15.78 is 87.666666666667% of 18