Keystones — Lintel
Five GCSE retrieval questions · 18 June 2026 · mathsvault.uk/keystones
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1. Number Product of primes
Write 72 as a product of its prime factors
Answer: 2³ × 3² -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 22 and 3x - y = 22
Answer: x = 8, y = 2 -
3. Geometry Pythagoras — short side
Calculate the missing side: a = 25cm, c = 38cm
Answer: 28.6cm -
4. Ratio Combining two ratios
a:b is 4:3 and b:c is 3:7. Find a:b:c.
Answer: 4:3:7 -
5. Statistics Expected frequency
A bag has 2 red out of 10 balls. If you pick 110 times (with replacement), how many times would you expect red?
Answer: 22