Keystones — Lintel
Five GCSE retrieval questions · 7 September 2017 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 420,000,000 in standard form
Answer: 4.2 × 108 -
2. Algebra Factorising monic quadratics
Factorise: x² - x - 90
Answer: (x + 9)(x - 10) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 15cm, angle = 60°. Find adjacent side
Answer: 7.5cm -
4. Ratio Mixed ratio problems
Simplify the ratio 1 litre : 450 ml
Answer: 20:9 -
5. Statistics Mean
The mean of 4 numbers is 31. If 3 of them are 20, 18, 19, what is the missing number?
Answer: 67