Keystones — Lintel
Five GCSE retrieval questions · 5 December 2010 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.00002 in standard form
Answer: 2 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² - 6x - 7
Answer: (x + 1)(x - 7) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 18cm, angle = 54°. Find adjacent side. Give your answer to 2 decimal places
Answer: 10.58cm -
4. Ratio Mixed ratio problems
Orange and purple marbles are in the ratio 10:9. What fraction of the marbles are purple?
Answer: 9⁄19 -
5. Statistics Mean
The mean of 5 numbers is 33. If 4 of them are 23, 49, 20, 23, what is the missing number?
Answer: 50