In a class of 30 children, the ratio of boys to girls is 3:2. How many boys are there?
Show worked explanation
The ratio 3:2 means 5 equal parts total (3+2=5). Divide 30 by 5 = 6 per part. Boys = 3 parts = 3 × 6 = 18 boys. ✓
11+ Ratio & Proportion Practice
(GL Assessment)
Ratio and proportion typically appears as two to four questions on a GL Assessment 11+ maths paper, where GL lists it as "simple ratio" within the statistics section. It covers sharing an amount in a given ratio, simplifying ratios, scaling recipes and reading map scales, plus the all-important link between ratios and fractions.
The GL maths paper is 50 multiple-choice questions in 50 minutes, with five options (A to E) per question. Ratio questions are almost always word problems, and the harder ones can need three or four calculation steps inside a single minute, so a quick, confident method matters as much as the arithmetic.
The reassuring part is that ratio rests on one core routine: add the parts, divide the total, then multiply back up. Once that becomes automatic, most GL ratio questions follow the same shape, and steady practice builds real speed and accuracy.
What the GL 11+ Tests on Ratio & Proportion
Every ratio question is multiple-choice with five options (A to E), almost always a word problem. In rough order of frequency, GL tests:
- Sharing in a two-part ratio (the most common): dividing a total between two people or groups.
- Simplifying ratios to their lowest terms using the highest common factor.
- Equivalent ratios and scaling: finding a missing value by scaling up or down.
- Recipe and mixture scaling: direct proportion using ingredients or paint mixes.
- Ratio-to-fraction conversion: the often-misunderstood idea that 3:4 means 3 out of 7.
- Sharing in a three-part ratio, and map scales and scale drawings.
- Proportion word problems using the unitary method (find the cost of one, then scale).
Difficulty ranges from simple sharing with friendly numbers (easy) to multi-step problems that work backwards from one person's share to find the total (hard). Inverse proportion is rare at 11+ and only appears in simple forms.
Ratio vs Fraction of an Amount and Percentage of an Amount: How to Tell Them Apart
Ratio, fractions and percentages all split an amount into parts, but describe the split differently. A ratio compares parts to each other, like 3:2. A fraction and a percentage compare a part to the whole, like 3/5 or 60%. The classic trap is reading a ratio as if it were a fraction of the total.
| Question type | What it tests | What it looks like | The classic mix-up |
|---|---|---|---|
| RatioThis page | Sharing an amount by comparing parts to each other, simplifying ratios, and scaling them up or down. | Two or more numbers joined by a colon, usually a sharing word problem. For example, "Share £45 between two friends in the ratio 4:5." | Reading the ratio 4:5 as the fraction 4/5 of the total, forgetting the parts add to nine. |
| Fraction of an Amount | Finding a stated fraction of a total by dividing by the denominator and multiplying by the numerator. | A fraction followed by "of" and an amount. For example, "What is 3/8 of 240?" | Treating 3/8 as a ratio of part to part, instead of a part of the whole amount. |
| Percentage of an Amount | Finding a stated percentage of a total, often via 10% and 1% building blocks or fraction shortcuts. | A percentage followed by "of" and an amount. For example, "What is 35% of 180?" | Confusing "percentage of" with sharing in a ratio, or with a percentage increase to be added on. |
If the numbers compare one part against another part (3:2), it is a ratio; if a single part is measured against the whole (3/5 or 60%), it is a fraction or percentage of the amount.
Sample Ratio & Proportion Questions
Five questions drawn from PrepStep’s ratio & proportion bank, spanning Foundation to Challenging. Tap “Show worked explanation” to see the full method after you’ve had a go. The correct answer is highlighted on each question so you can check immediately.
Tom and Jerry share 80 marbles in the ratio 3:5. How many marbles does Jerry get?
Show worked explanation
Total parts: 3 + 5 = 8 parts. Each part = 80 ÷ 8 = 10 marbles. Jerry gets 5 parts = 5 × 10 = 50 marbles. ✓
Andrew and Matthew share 96 sweets in the ratio 5:3. How many more sweets does Andrew get than Matthew?
Show worked explanation
Total parts: 5 + 3 = 8. Each part = 96 ÷ 8 = 12. Andrew gets 5 × 12 = 60, Matthew gets 3 × 12 = 36. Difference: 60 - 36 = 24. ✓
A milkshake recipe uses 4 spoonfuls of syrup for 300ml of milk. How many spoonfuls are needed for 750ml of milk?
Show worked explanation
750ml is 2.5 times 300ml (750 ÷ 300 = 2.5). So syrup needed = 4 × 2.5 = 10 spoonfuls. ✓
A model of a building is made to scale 1:50. If the model is 60cm tall, how tall is the real building in metres?
Show worked explanation
Real height = 60 × 50 = 3000cm = 30 metres. ✓
Common Mistakes to Avoid
Common mistake 1 of 4
Confusing part-to-part with part-to-whole.
Tip: The ratio 3:4 means 3 out of every 7, not 3 out of 4. Add the parts to get the whole first, then any fraction question becomes "this part out of the total".
Common mistake 2 of 4
Adding instead of multiplying (the additive error).
Tip: Seeing 2 become 6 and adding 4 to 3 to get 7, instead of multiplying by 3 to get 9. Always ask "how many times bigger?", never "how much was added?".
Common mistake 3 of 4
Giving the wrong share, or the wrong thing entirely.
Tip: Children mix up who gets which share, or give one person's share when the question asked for the total. Underline exactly what is being asked before calculating.
Common mistake 4 of 4
Not simplifying a ratio fully.
Tip: Reducing 12:18 to 6:9 and stopping, instead of going on to 2:3. After simplifying, check the parts share no further common factor.
About these questions
Every PrepStep 11+ question is original, written to mirror the style and difficulty of the GL Assessment 11+ and grounded in a library of real past-paper patterns, with a worked explanation for each one. PrepStep is built by Ben Jackson, its founder and a parent who has taken one child through the 11+ with another preparing now. Last reviewed: August 2026.
Frequently Asked Questions
What is ratio and proportion in the 11+ maths exam?
Ratio compares quantities, written as a:b, and proportion describes a part of a whole. In the GL 11+, children share amounts in a ratio, simplify ratios, scale recipes and maps, and convert between ratios and fractions. Questions are word problems, always multiple-choice with five options.
Is 3:4 the same as 3/4 in a ratio?
No, and this is the single most common ratio mistake. The ratio 3:4 has 3 parts and 4 parts, making 7 parts in total, so the first quantity is 3/7 of the whole, not 3/4. Always add the parts to find the whole before writing a fraction.
How do you answer ratio sharing questions in the 11+?
Follow three steps: add the ratio parts to get the total number of parts, divide the amount by that total to find the value of one part, then multiply each ratio number by the value of one part. Finally, check the shares add back up to the original total.
How many ratio questions are in the GL 11+ maths paper?
Typically two to four per paper. Ratio sits within the statistics section, which is smaller than the number-heavy core of the paper, but ratio ideas also turn up inside number and money problems, so the skill is worth more than the question count suggests.
How can my child practise ratio for the GL 11+?
Use timed, five-option word problems that match the exam. Make the "add the parts, divide, multiply back" routine automatic first, then drill the ratio-to-fraction link (3:4 means 3/7) because GL exploits it constantly. Add three-part ratios, recipe scaling and working-backwards questions once the basics are secure.
What is the difference between ratio, fractions and percentages of an amount in the 11+?
A ratio compares parts to one another: sharing 40 in the ratio 3:2 means splitting it into 3 parts and 2 parts. A fraction or percentage of an amount compares a part to the whole: 3/5 of 40, or 60% of 40. The key is that 3:2 has five parts in total, so the larger share is 3/5, not 3/4. GL deliberately tests this ratio-to-fraction link.
More 11+ Maths Practice
Explore the other GL Assessment maths topics, each with free sample questions and worked explanations.
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