Answer:
A: 212.5
Step-by-step explanation:
1. We assume, that the number 212.5 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 212.5 is 100%, so we can write it down as 212.5=100%.
4. We know, that x is 40% of the output value, so we can write it down as x=40%.
5. Now we have two simple equations:
1) 212.5=100%
2) x=40%
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:
212.5/x=100%/40%
6. Now we just have to solve the simple equation, and we will get the solution we are looking for.
7. Solution for what is 40% of 212.5
212.5/x=100/40
(212.5/x)*x=(100/40)*x - we multiply both sides of the equation by x
212.5=2.5*x - we divide both sides of the equation by (2.5) to get x
212.5/2.5=x
85=x
x=85
