Keystones — Capstone
Five GCSE retrieval questions · 12 September 2025 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √75
Answer: 5√3 -
2. Algebra Completing the square
Complete the square: x² + 2.8x
Answer: (x + 1.4)² - 1.96 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 18cm, b = 30cm, angle = 63°
Answer: 240.6cm² -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 2:3. Find a:b:c.
Answer: 2:4:6 -
5. Statistics Averages and range
Find the mean, median and range of: 42, 76, 78, 20, 91, 10, 19, 95
Answer: Mean = 53.9, Median = 76, Range = 85