Keystones — Lintel
Five GCSE retrieval questions · 13 January 2011 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.072 in standard form
Answer: 7.2 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² + 6x - 55
Answer: (x + 11)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 24cm, angle = 32°. Find opposite. Give your answer to 2 decimal places
Answer: 15cm -
4. Ratio Mixed ratio problems
Black, white and yellow marbles are in the ratio 12:11:1. What fraction of the marbles are black?
Answer: 1⁄2 -
5. Statistics Mean
The mean of 6 numbers is 25. If 5 of them are 46, 15, 16, 32, 16, what is the missing number?
Answer: 25