Keystones — Lintel
Five GCSE retrieval questions · 8 January 2014 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.00051 in standard form
Answer: 5.1 × 10-4 -
2. Algebra Factorising monic quadratics
Factorise: x² - 13x + 30
Answer: (x - 3)(x - 10) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 19cm, angle = 58°. Find opposite. Give your answer to 2 decimal places
Answer: 30.41cm -
4. Ratio Mixed ratio problems
Black and white beads are in the ratio 3:13. What fraction of the beads are white?
Answer: 13⁄16 -
5. Statistics Mean
The mean of 4 numbers is 25. If 3 of them are 24, 26, 30, what is the missing number?
Answer: 20