Mathematics for IGCSE & O level - Ratio And Proportion (Section 3 - No. 50)
Which scenarios exemplify direct proportion?
The amount of money earned and the number of hours worked at a constant hourly rate.
The number of items bought and their total cost.
The time to fill a tank and the volume of water added.
The side of a square and its area.
Explanation
Direct proportion means as one value goes up, the other increases as well, (or they both decrease).