Keystones — Lintel
Five GCSE retrieval questions · 2 August 2017 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 42,000,000 in standard form
Answer: 4.2 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² - 2x - 15
Answer: (x + 3)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 28cm, angle = 26°. Find adjacent side. Give your answer to 2 decimal places
Answer: 25.17cm -
4. Ratio Mixed ratio problems
Black, white and yellow marbles are in the ratio 8:10:12. What fraction of the marbles are black?
Answer: 4⁄15 -
5. Statistics Mean
The mean of 4 numbers is 26. If 3 of them are 23, 24, 40, what is the missing number?
Answer: 17