Keystones — Lintel
Five GCSE retrieval questions · 26 February 2015 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 230,000,000 in standard form
Answer: 2.3 × 108 -
2. Algebra Factorising monic quadratics
Factorise: x² - 2x - 15
Answer: (x + 3)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 16cm, angle = 53°. Find opposite. Give your answer to 2 decimal places
Answer: 21.23cm -
4. Ratio Mixed ratio problems
In ratio 12:4:5, what fraction is the third part?
Answer: 5⁄21 -
5. Statistics Mean
The mean of 5 numbers is 31. If 4 of them are 27, 42, 31, 17, what is the missing number?
Answer: 38