Keystones — Lintel
Five GCSE retrieval questions · 28 September 2014 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 43,000,000 in standard form
Answer: 4.3 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² + 7x - 30
Answer: (x + 10)(x - 3) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 27cm, angle = 38°. Find opposite. Give your answer to 2 decimal places
Answer: 21.09cm -
4. Ratio Mixed ratio problems
Black and white beads are in the ratio 9:11. What fraction of the beads are black?
Answer: 9⁄20 -
5. Statistics Mean
The mean of 6 numbers is 29. If 5 of them are 43, 44, 30, 25, 23, what is the missing number?
Answer: 9