Keystones — Capstone
Five GCSE retrieval questions · 28 July 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: 16x² + 0x - 25
Answer: (4x - 5)(4x + 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 29cm, angle = 55°. Find opposite
Answer: 41.4cm -
4. Ratio Reverse percentages
A price of £332.74 includes a 27% increase. What was the price before the increase?
Answer: £262.00 -
5. Statistics Mean
The mean of 6 numbers is 31. If 5 of them are 43, 31, 49, 33, 16, what is the missing number?
Answer: 14