Keystones — Lintel
Five GCSE retrieval questions · 8 December 2013 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 850,000,000 in standard form
Answer: 8.5 × 108 -
2. Algebra Factorising monic quadratics
Factorise: x² + 3x - 40
Answer: (x + 8)(x - 5) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 28cm, angle = 40°. Find opposite. Give your answer to 2 decimal places
Answer: 23.49cm -
4. Ratio Mixed ratio problems
Simplify the ratio 1 hour : 20 minutes
Answer: 3:1 -
5. Statistics Mean
The mean of 5 numbers is 31. If 4 of them are 50, 21, 22, 33, what is the missing number?
Answer: 29