Keystones — Lintel
Five GCSE retrieval questions · 21 November 2011 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 770,000,000 in standard form
Answer: 7.7 × 108 -
2. Algebra Factorising monic quadratics
Factorise: x² - 5x - 84
Answer: (x + 7)(x - 12) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 21cm, angle = 50°. Find adjacent side. Give your answer to 2 decimal places
Answer: 13.5cm -
4. Ratio Mixed ratio problems
Black and white sweets are in the ratio 13:6. What fraction of the sweets are white?
Answer: 6⁄19 -
5. Statistics Mean
The mean of 6 numbers is 25. If 5 of them are 23, 24, 19, 28, 15, what is the missing number?
Answer: 41