Keystones — Lintel
Five GCSE retrieval questions · 23 October 2013 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 27,000,000 in standard form
Answer: 2.7 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² - 9x - 36
Answer: (x + 3)(x - 12) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 28cm, angle = 59°. Find opposite. Give your answer to 2 decimal places
Answer: 46.6cm -
4. Ratio Mixed ratio problems
Black and white marbles are in the ratio 7:9. What fraction of the marbles are black?
Answer: 7⁄16 -
5. Statistics Mean
The mean of 4 numbers is 32. If 3 of them are 38, 37, 45, what is the missing number?
Answer: 8