Keystones — Lintel
Five GCSE retrieval questions · 23 January 2015 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 6,300,000 in standard form
Answer: 6.3 × 106 -
2. Algebra Factorising monic quadratics
Factorise: x² + 4x - 21
Answer: (x + 7)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 31cm, angle = 28°. Find adjacent side. Give your answer to 2 decimal places
Answer: 27.37cm -
4. Ratio Mixed ratio problems
Black, white and yellow marbles are in the ratio 8:2:11. What fraction of the marbles are yellow?
Answer: 11⁄21 -
5. Statistics Mean
The mean of 5 numbers is 24. If 4 of them are 33, 15, 30, 20, what is the missing number?
Answer: 22