Keystones — Capstone
Five GCSE retrieval questions · 22 July 2026 · mathsvault.uk/keystones
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1. Number Error intervals
55 is rounded to the nearest integer. What is the error interval?
Answer: 54.5 ≤ x < 55.5 -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 16 and 3x - y = 13
Answer: x = 5, y = 2 -
3. Geometry Distance between two points
Find the distance between (0, -6) and (7, 12)
Answer: 19.31 -
4. Ratio Repeated percentage change
A car worth £19,641.00 depreciates by 22% each year for 3 years. What is it worth after 3 years?
Answer: £9,320.68 -
5. Statistics Expected frequency
A bag has 5 red out of 13 balls. If you pick 56 times (with replacement), how many times would you expect red?
Answer: 21.5