Three relationships are described below: I. The amount of fuel used on a trip increases as the size of the car increases and as the distance traveled increases.

II. As the number of people helping mow a lawn increases, the time it takes to mow the lawn decreases.

III. The cost of having a house painted increases as the size of the house increases.

What type of variation describes each relationship?

I is direct, II is joint, and III is inverse.

I is joint, II is inverse, and III is direct.

I is joint, II is direct, and III is inverse.

I is direct, II is inverse, and III is joint.