Keystones — Capstone
Five GCSE retrieval questions · 2 March 2026 · mathsvault.uk/keystones
-
1. Number Rationalising the denominator
Rationalise the denominator: 6/√12
Answer: √3 (or 3√3⁄3) -
2. Algebra Factorising non-monic quadratics
Factorise: 8x² + 8x - 6
Answer: (4x - 2)(2x + 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 12cm, angle = 57°. Find opposite
Answer: 18.5cm -
4. Ratio Reverse percentages
A price of £776.25 includes a 35% increase. What was the price before the increase?
Answer: £575.00 -
5. Statistics Mean
The mean of 6 numbers is 31. If 5 of them are 16, 43, 33, 38, 45, what is the missing number?
Answer: 11