Keystones — Lintel
Five GCSE retrieval questions · 11 March 2013 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.000083 in standard form
Answer: 8.3 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² - 10x + 21
Answer: (x - 3)(x - 7) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 10cm, angle = 35°. Find opposite. Give your answer to 2 decimal places
Answer: 7cm -
4. Ratio Mixed ratio problems
Divide 140 in the ratio 2:2:3
Answer: 40, 40 and 60 -
5. Statistics Mean
The mean of 6 numbers is 31. If 5 of them are 40, 15, 37, 25, 44, what is the missing number?
Answer: 25