Keystones — Lintel
Five GCSE retrieval questions · 21 April 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
0.087
Answer: 8.7 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² - 10x + 25
Answer: (x - 5)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 22cm, angle = 43°. Find opposite
Answer: 20.5cm -
4. Ratio Mixed ratio problems
Divide 105 in the ratio 1:4:2
Answer: 15, 60 and 30 -
5. Statistics Mean
The mean of 5 numbers is 22. If 4 of them are 50, 16, 40, 30, what is the missing number?
Answer: -26