Keystones — Lintel
Five GCSE retrieval questions · 6 September 2012 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 0.0022 in standard form
Answer: 2.2 × 10-3 -
2. Algebra Factorising monic quadratics
Factorise: x² - 6x - 7
Answer: (x + 1)(x - 7) -
3. Geometry SOHCAHTOA — missing length
Hypotenuse = 20cm, angle = 39°. Find adjacent side. Give your answer to 2 decimal places
Answer: 15.54cm -
4. Ratio Mixed ratio problems
Red and blue beads are in the ratio 15:13. What fraction of the beads are red?
Answer: 15⁄28 -
5. Statistics Mean
The mean of 5 numbers is 31. If 4 of them are 34, 21, 46, 46, what is the missing number?
Answer: 8