Practice Inverse Quantity in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

A relationship where one quantity increases as another decreases, with constant product.

More workers = less time to finish. Double the workers, halve the time.

Example 1

easy
If 5 workers can complete a job in 12 days, how many days will it take 15 workers (assuming equal work rates)?

Example 2

medium
The pressure P of a gas varies inversely with its volume V at constant temperature (Boyle's Law). If P = 200 kPa when V = 3 L, find P when V = 5 L.

Example 3

easy
At 60 km/h a trip takes 4 hours. How long does the same trip take at 80 km/h?

Example 4

medium
Variables x and y are inversely proportional. When x = 4, y = 9. Find y when x = 12, and find x when y = 6.