85 is 40% of what number

A: 212.5

B: 47.1

C: 34

D:45

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

212.5

Step-by-step explanation:

is/of=%/100