Keystones — Lintel
Five GCSE retrieval questions · 8 August 2026 · mathsvault.uk/keystones
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1. Number Product of primes
Express 144 as a product of prime factors
Answer: 2⁴ × 3² -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 24 and 3x - y = 3
Answer: x = 3, y = 6 -
3. Geometry Pythagoras — short side
Calculate the missing side: a = 24cm, c = 41cm
Answer: 33.2cm -
4. Ratio Combining two ratios
a:b is 4:3 and b:c is 3:4. Find a:b:c.
Answer: 4:3:4 -
5. Statistics Expected frequency
A bag has 2 red out of 14 balls. If you pick 150 times (with replacement), how many times would you expect red?
Answer: 21.4