Keystones — Lintel
Five GCSE retrieval questions · 11 March 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 = 10 and 2x + y = 6
Answer: x = 2, y = 2 -
3. Geometry Pythagoras — short side
Calculate the missing side: a = 15cm, c = 32cm
Answer: 28.3cm -
4. Ratio Combining two ratios
a:b is 3:4 and b:c is 1:3. Find a:b:c.
Answer: 3:4:12 -
5. Statistics Expected frequency
A fair coin is flipped 110 times. How many heads would you expect?
Answer: 55