Keystones — Lintel
Five GCSE retrieval questions · 17 December 2014 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.041 in standard form
Answer: 4.1 × 10-2 -
2. Algebra Factorising monic quadratics
Factorise: x² + 7x - 30
Answer: (x + 10)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 15cm, angle = 39°. Find opposite. Give your answer to 2 decimal places
Answer: 12.15cm -
4. Ratio Mixed ratio problems
Simplify: 15:6:6
Answer: 5:2:2 -
5. Statistics Mean
The mean of 4 numbers is 31. If 3 of them are 15, 21, 50, what is the missing number?
Answer: 38