Keystones — Lintel
Five GCSE retrieval questions · 14 March 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 = 18 and 3x - y = 16
Answer: x = 6, y = 2 -
3. Geometry Pythagoras — short side
Calculate the missing side: a = 13cm, c = 33cm
Answer: 30.3cm -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 4:5. Find a:b:c.
Answer: 2:4:5 -
5. Statistics Expected frequency
A fair coin is flipped 128 times. How many heads would you expect?
Answer: 64