Keystones — Lintel
Five GCSE retrieval questions · 24 May 2025 · mathsvault.uk/keystones
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1. Number Converting to standard form
0.00083
Answer: 8.3 × 10-4 -
2. Algebra Factorising monic quadratics
Factorise: x² - 8x + 15
Answer: (x - 5)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 27cm, angle = 52°. Find opposite
Answer: 34.6cm -
4. Ratio Mixed ratio problems
Divide 68 in the ratio 2:1:1
Answer: 34, 17 and 17 -
5. Statistics Mean
The mean of 6 numbers is 34. If 5 of them are 23, 43, 17, 30, 48, what is the missing number?
Answer: 43