Question

Appropriate units

Abedabun wants to model how a car's maintenance costs change as the distance someone drives the car
increases.
What would be an appropriate unit for Abedabun's purpose?
Choose 1 answer:
m/mL $/km mL/m km/$​

Answer 1

$/km would be the right answer

Explanation:

I did it on khan academy

Answer 2

"$/km"

Explanation:

He wants to model "maintenance cost" with respect to "distance"

Normally,

maintenance cost would be in currency --- dollars, pounds etc.

distance would be in kilometers, miles, meters etc.

We need to find the ratio that has the COST on top and DISTANCE on bottom

Looking at the choices,

We can eliminate 1st and 3rd immediately as it doesn't have COST on top.

That leaves us with

$/km

and

km/$

$ is in fact currency and unit for cost and km is in fact unit for distance. We need the ratio that has $ on top and km on bottom, that's the 2nd option.

So, $/km is the appropriate unit.