Keystones — Lintel
Five GCSE retrieval questions · 28 August 2012 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.000015 in standard form
Answer: 1.5 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² + 8x - 9
Answer: (x + 9)(x - 1) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 21cm, angle = 44°. Find opposite. Give your answer to 2 decimal places
Answer: 20.28cm -
4. Ratio Mixed ratio problems
Simplify the ratio 2 litres : 800 ml
Answer: 5:2 -
5. Statistics Mean
The mean of 4 numbers is 30. If 3 of them are 45, 27, 37, what is the missing number?
Answer: 11