Keystones — Lintel
Five GCSE retrieval questions · 2 January 2013 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.00061 in standard form
Answer: 6.1 × 10-4 -
2. Algebra Factorising monic quadratics
Factorise: x² + 10x + 21
Answer: (x + 7)(x + 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 12cm, angle = 53°. Find opposite. Give your answer to 2 decimal places
Answer: 15.92cm -
4. Ratio Mixed ratio problems
Simplify the ratio 3 hours : 25 minutes
Answer: 36:5 -
5. Statistics Mean
The mean of 4 numbers is 36. If 3 of them are 22, 50, 20, what is the missing number?
Answer: 52