Keystones — Lintel
Five GCSE retrieval questions · 4 August 2010 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.0045 in standard form
Answer: 4.5 × 10-3 -
2. Algebra Factorising monic quadratics
Factorise: x² + 7x - 30
Answer: (x + 10)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 23cm, angle = 38°. Find opposite. Give your answer to 2 decimal places
Answer: 17.97cm -
4. Ratio Mixed ratio problems
Black and white beads are in the ratio 11:6. What fraction of the beads are white?
Answer: 6⁄17 -
5. Statistics Mean
The mean of 6 numbers is 25. If 5 of them are 32, 33, 35, 25, 20, what is the missing number?
Answer: 5