Keystones — Capstone
Five GCSE retrieval questions · 17 January 2026 · mathsvault.uk/keystones
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1. Number Rationalising the denominator
Rationalise: 5/√2
Answer: 5√2⁄2 -
2. Algebra Factorising non-monic quadratics
Factorise: 6x² + 4x - 10
Answer: (2x - 2)(3x + 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 12cm, angle = 35°. Find opposite
Answer: 8.4cm -
4. Ratio Reverse percentages
A price of £555.10 includes a 30% increase. What was the price before the increase?
Answer: £427.00 -
5. Statistics Mean
The mean of 5 numbers is 40. If 4 of them are 45, 47, 43, 16, what is the missing number?
Answer: 49