Keystones — Lintel
Five GCSE retrieval questions · 4 October 2014 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.00015 in standard form
Answer: 1.5 × 10-4 -
2. Algebra Factorising monic quadratics
Factorise: x² - x - 42
Answer: (x + 6)(x - 7) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 20cm, angle = 49°. Find opposite. Give your answer to 2 decimal places
Answer: 23.01cm -
4. Ratio Mixed ratio problems
In ratio 8:7:1, what fraction is the third part?
Answer: 1⁄16 -
5. Statistics Mean
The mean of 4 numbers is 33. If 3 of them are 42, 22, 23, what is the missing number?
Answer: 45