Keystones — Lintel
Five GCSE retrieval questions · 9 January 2017 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.000051 in standard form
Answer: 5.1 × 10-5 -
2. Algebra Factorising monic quadratics
Factorise: x² + x - 72
Answer: (x + 9)(x - 8) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 14cm, angle = 52°. Find opposite. Give your answer to 2 decimal places
Answer: 17.92cm -
4. Ratio Mixed ratio problems
Simplify the ratio 2 hours : 40 minutes
Answer: 3:1 -
5. Statistics Mean
The mean of 5 numbers is 33. If 4 of them are 35, 47, 50, 21, what is the missing number?
Answer: 12