Keystones — Capstone
Five GCSE retrieval questions · 27 October 2026 · mathsvault.uk/keystones
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1. Number Error intervals
74 is rounded to the nearest integer. What is the error interval?
Answer: 73.5 ≤ x < 74.5 -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 33 and 3x - y = 22
Answer: x = 9, y = 5 -
3. Geometry Distance between two points
Find the distance between (2, -3) and (7, 4)
Answer: 8.6 -
4. Ratio Repeated percentage change
A car worth £17,569.00 depreciates by 21% each year for 3 years. What is it worth after 3 years?
Answer: £8,662.20 -
5. Statistics Expected frequency
A bag has 2 red out of 9 balls. If you pick 90 times (with replacement), how many times would you expect red?
Answer: 20