NumberDeep Dive

Method: Inverse Proportion

Part of Proportion · GCSE GCSE Mathematics revision

This deep dive covers Method: Inverse Proportion within Proportion for GCSE Mathematics. Revise Proportion in Number for GCSE Mathematics with 12 exam-style questions and 22 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 5 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 5 of 16

Practice

12 questions

Recall

22 flashcards

Method: Inverse Proportion

1 Write y = k/x (y is inversely proportional to x)

2 Use given values to find k

3 Substitute k back into equation

4 Use equation to find unknown values

5 Example: If y ∝ 1/x and y = 8 when x = 2, find k = 8×2 = 16, so y = 16/x

Keep building this topic

Read this section alongside the surrounding pages in Proportion. That gives you the full topic sequence instead of a single isolated revision point.

Method: Direct Proportion Visual Understanding The Language of Relationships What is Proportion?

Practice Questions for Proportion

y is directly proportional to x. Which equation could represent this relationship?

A. y = k/x
B. y = kx
C. y = k − x
D. y = x²

1 markfoundation

Explain how you can tell from a graph whether two quantities are in direct or inverse proportion.

2 marksstandard

Quick Recall Flashcards

Proportion Symbol

∝ means 'proportional to' Examples: y ∝ x (y is proportional to x) y ∝ 1/x (y is inversely proportional to x)

Recipe Application

Recipe for 4 people uses 300g flour How much for 10 people? Flour ∝ People (direct) F = kP 300 = k × 4, so k = 75 For 10 people: F = 75 × 10 = 750g

12 questions on Proportion — practise free

Instant marking, adaptive difficulty, and 22 spaced repetition flashcards. Free until your GCSEs.

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Method: Direct Proportion

Visual Understanding