Keystones — Lintel
Five GCSE retrieval questions · 13 May 2012 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.000076 in standard form
Answer: 7.6 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² + 4x - 21
Answer: (x + 7)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 22cm, angle = 50°. Find opposite. Give your answer to 2 decimal places
Answer: 26.22cm -
4. Ratio Mixed ratio problems
Black, white and yellow marbles are in the ratio 1:10:2. What fraction of the marbles are white?
Answer: 10⁄13 -
5. Statistics Mean
The mean of 4 numbers is 38. If 3 of them are 32, 42, 28, what is the missing number?
Answer: 50