Keystones — Lintel
Five GCSE retrieval questions · 7 August 2026 · mathsvault.uk/keystones
-
1. Number Product of primes
Express 200 as a product of prime factors
Answer: 2³ × 5² -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 14 and 3x - y = 10
Answer: x = 4, y = 2 -
3. Geometry Pythagoras — short side
Calculate the missing side: a = 17cm, c = 35cm
Answer: 30.6cm -
4. Ratio Combining two ratios
a:b is 2:5 and b:c is 5:4. Find a:b:c.
Answer: 2:5:4 -
5. Statistics Expected frequency
A bag has 2 red out of 13 balls. If you pick 97 times (with replacement), how many times would you expect red?
Answer: 14.9