Keystones — Capstone
Five GCSE retrieval questions · 19 April 2026 · mathsvault.uk/keystones
-
1. Number Error intervals
41 is rounded to the nearest integer. What is the error interval?
Answer: 40.5 ≤ x < 41.5 -
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, -3) and (11, 4)
Answer: 12.21 -
4. Ratio Repeated percentage change
A car worth £12,684.00 depreciates by 14% each year for 4 years. What is it worth after 4 years?
Answer: £6,938.25 -
5. Statistics Expected frequency
A bag has 4 red out of 11 balls. If you pick 97 times (with replacement), how many times would you expect red?
Answer: 35.3