Keystones — Lintel
Five GCSE retrieval questions · 19 October 2026 · mathsvault.uk/keystones
-
1. Number Converting to standard form
45000
Answer: 4.5 × 104 -
2. Algebra Factorising monic quadratics
Factorise: x² - 12x + 35
Answer: (x - 5)(x - 7) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 30cm, angle = 60°. Find adjacent side
Answer: 15cm -
4. Ratio Mixed ratio problems
Divide 90 in the ratio 3:2:4
Answer: 30, 20 and 40 -
5. Statistics Mean
The mean of 5 numbers is 24. If 4 of them are 21, 17, 19, 43, what is the missing number?
Answer: 20