Keystones — Capstone
Five GCSE retrieval questions · 9 September 2026 · mathsvault.uk/keystones
-
1. Number Error intervals
61 is rounded to the nearest integer. What is the error interval?
Answer: 60.5 ≤ x < 61.5 -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 31 and 3x - y = 19
Answer: x = 8, y = 5 -
3. Geometry Distance between two points
Find the distance between (1, -7) and (8, 5)
Answer: 13.89 -
4. Ratio Repeated percentage change
A car worth £6,825.00 depreciates by 18% each year for 4 years. What is it worth after 4 years?
Answer: £3,085.73 -
5. Statistics Expected frequency
A bag has 3 red out of 12 balls. If you pick 78 times (with replacement), how many times would you expect red?
Answer: 19.5