Keystones — Capstone
Five GCSE retrieval questions · 24 February 2026 · mathsvault.uk/keystones
-
1. Number Error intervals
51 is rounded to the nearest integer. What is the error interval?
Answer: 50.5 ≤ x < 51.5 -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 24 and 3x - y = 14
Answer: x = 6, y = 4 -
3. Geometry Distance between two points
Find the distance between (-8, -3) and (3, 10)
Answer: 17.03 -
4. Ratio Repeated percentage change
A car worth £19,293.00 depreciates by 19% each year for 5 years. What is it worth after 5 years?
Answer: £6,727.05 -
5. Statistics Expected frequency
A bag has 4 red out of 11 balls. If you pick 114 times (with replacement), how many times would you expect red?
Answer: 41.5