MathsYears 9–11Ratio & Proportion

Inverse proportion

Learn Inverse proportion for Years 9–11 pupils (ages 13–16). Free practice questions, lessons and worked examples — aligned to the UK National Curriculum.

What you'll learn

  1. 1

    In inverse proportion, as one quantity increases the other decreases — and their PRODUCT stays constant.

  2. 2

    If 4 workers take 6 days, the total work is 4 × 6 = 24 worker-days. With 8 workers: 24 ÷ 8 = 3 days.

  3. 3

    In inverse proportion, what stays the same?

  4. 4

    Not everything that decreases is inverse proportion. Check whether the product really is constant.

  5. 5

    A journey takes 3 hours at 40 mph. Distance = 120 miles. At 60 mph: 120 ÷ 60 = 2 hours.

  6. 6

    6 taps fill a tank in 20 minutes. How long would 12 taps take?

  7. 7

    What shape is a graph of inverse proportion?

Practise Inverse proportion with Whizlo

Free AI-tutored lessons, unlimited practice questions, and progress tracking for ages 13–16. Aligned to the UK National Curriculum.