138.5 is what percent of 155 - 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 155 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 155, so we can write it down as 100%=155.
4. We know, that x% equals 138.5 of the output value, so we can write it down as x%=138.5.
5. Now we have two simple equations:
1) 100%=155
2) x%=138.5
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%=155/138.5
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for 138.5 is what percent of 155

100%/x%=155/138.5
(100/x)*x=(155/138.5)*x       - we multiply both sides of the equation by x
100=1.1191335740072*x       - we divide both sides of the equation by (1.1191335740072) to get x
100/1.1191335740072=x
89.354838709677=x
x=89.354838709677

now we have:
138.5 is 89.354838709677% of 155