Keystones — Lintel
Five GCSE retrieval questions · 20 November 2012 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 21,000,000 in standard form
Answer: 2.1 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² - 4x - 12
Answer: (x + 2)(x - 6) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 15cm, angle = 28°. Find adjacent side. Give your answer to 2 decimal places
Answer: 13.24cm -
4. Ratio Mixed ratio problems
Red, blue and green beads are in the ratio 10:4:7. What fraction of the beads are red?
Answer: 10⁄21 -
5. Statistics Mean
The mean of 6 numbers is 35. If 5 of them are 17, 45, 45, 32, 36, what is the missing number?
Answer: 35