Keystones — Lintel
Five GCSE retrieval questions · 2 May 2026 · mathsvault.uk/keystones
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1. Number Product of primes
Write 48 as a product of its prime factors
Answer: 2⁴ × 3 -
2. Algebra Linear simultaneous equations
Solve: 2x + 3y = 16 and 3x - y = 13
Answer: x = 5, y = 2 -
3. Geometry Pythagoras — short side
Find b if a = 6cm and c = 13cm
Answer: 11.53cm -
4. Ratio Combining two ratios
a:b is 1:2 and b:c is 2:3. Find a:b:c.
Answer: 2:4:6 -
5. Statistics Expected frequency
A bag has 5 red out of 10 balls. If you pick 91 times (with replacement), how many times would you expect red?
Answer: 45.5