Unit 8 · Rates and Ratios
Sports Drink Ratio — Scale the Recipe
Lesson 2 of 3
Ratio scaling always starts with total parts: add the ratio numbers, divide the given amount by that total, then multiply each part you need.
Mixture and sharing ratios appear throughout Selective MR — students who find “how many groups” first avoid cross-multiplying under pressure.
The examiner checks whether you can scale a part-to-part ratio to a real total (e.g. litres of drink) using unit groups, not guesswork.
Two ingredients are mixed in a fixed ratio. A total amount of mixture is made. You find how much of one ingredient is required.
Best approach: Add ratio parts (5 + 2 = 7). One group size = total ÷ 7. Multiply the required part (concentrate = 2 groups) by that size.
Question
A sports drink is made by mixing water and concentrate in the ratio 5 : 2.
How much concentrate is needed to make 3.5 litres of drink?
Select an answer to see the explanation.
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