Keystones — Lintel
Five GCSE retrieval questions · 13 May 2015 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.000081 in standard form
Answer: 8.1 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² + x - 20
Answer: (x + 5)(x - 4) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 15cm, angle = 60°. Find opposite. Give your answer to 2 decimal places
Answer: 25.98cm -
4. Ratio Mixed ratio problems
Red, blue and green counters are in the ratio 1:1:9. What fraction of the counters are red?
Answer: 1⁄11 -
5. Statistics Mean
The mean of 6 numbers is 30. If 5 of them are 24, 18, 17, 43, 49, what is the missing number?
Answer: 29