Keystones — Capstone
Five GCSE retrieval questions · 17 October 2025 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √108
Answer: 6√3 -
2. Algebra Completing the square
Complete the square: x² + 3.6x
Answer: (x + 1.8)² - 3.24 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 17cm, b = 13cm, angle = 60°
Answer: 95.7cm² -
4. Ratio Combining two ratios
a:b is 3:4 and b:c is 2:3. Find a:b:c.
Answer: 3:4:6 -
5. Statistics Averages and range
Find the mean, median and range of: 73, 33, 85, 69, 23, 62, 90, 77, 34
Answer: Mean = 60.7, Median = 69, Range = 67