Keystones — Lintel
Five GCSE retrieval questions · 22 August 2012 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.025 in standard form
Answer: 2.5 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² + 10x + 21
Answer: (x + 7)(x + 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 14cm, angle = 48°. Find opposite. Give your answer to 2 decimal places
Answer: 15.55cm -
4. Ratio Mixed ratio problems
Red and blue marbles are in the ratio 11:10. What fraction of the marbles are red?
Answer: 11⁄21 -
5. Statistics Mean
The mean of 6 numbers is 40. If 5 of them are 37, 42, 34, 34, 44, what is the missing number?
Answer: 49