EST. 2024 · LONDON·MMXXVI SPECIFICATION
AQA·Edexcel·OCR|Foundation + Higher
Ratio, Proportion & Rates of Change

Sheet № 114 · Foundation + Higher · AQA · Edexcel · OCR

114

Sharing in a Ratio –

Sharing in a ratio is one of the most frequently tested skills in GCSE Maths. Whether you are splitting money between friends, dividing ingredients for a recipe, or working out how much paint to mix, the method is always the same. This guide covers every variation you will meet in the exam — sharing with a total given, sharing with a diff

§Key definitions

Question:

Share £360 between Amy and Ben in the ratio 4 : 5.

Answer:

Amy gets £160 and Ben gets £200.

Q1 (Foundation):

Share £540 between two charities in the ratio 2 : 7.

Q2 (Foundation):

Divide 72 marbles among three children in the ratio 1 : 3 : 5.

Q3 (Higher):

Sam and Jake share money in the ratio 4 : 9. Jake receives £35 more than Sam. How much does each person receive?

§Formulas to memorise

Value of one part = Total amount ÷ Sum of ratio parts

Each share = Number of parts × Value of one part

Add the parts — of the ratio together to find the total number of parts.

Divide — the given amount by the total parts to find the value of one part.

Multiply — each number in the ratio by the value of one part to find each share.

Check — your answers add up to the original total.

Worked example

Share £360 between Amy and Ben in the ratio 4 : 5.

Working: Total parts = 4 + 5 = 9. Value of one part = £360 ÷ 9 = £40. Amy receives 4 × £40 = £160. Ben receives 5 × £40 = £200. Check: £160 + £200 = £360 ✓

Common mistakes

  • Dividing by a ratio part instead of the total. If the ratio is 3 : 5 and you are given the total, divide by 8 (the sum), not by 3 or by 5.
  • Mixing up the order. "Alice to Bob in the ratio 2 : 7" means Alice gets 2 parts. Read the names and the numbers in the same order.
  • Forgetting to check. Always verify your shares add up to the total. This catches arithmetic slips before they cost you marks.

Exam tips

  • Write "Total parts = ..." as your first line of working. Examiners look for this and award a method mark.
  • When given a difference, find the difference in parts first, then calculate one part from there.
  • If one share is given directly, divide that share by its number of parts to find the value of one part immediately.
  • Questions sometimes express ratios using fractions (e.g., ½ : ⅓). Multiply both sides by the LCM to clear fractions before sharing.
MMXXVI specification · AQA · Edexcel · OCRgcsemathsai.co.uk/formulas/sharing-in-a-ratio