Keystones — Lintel
Five GCSE retrieval questions · 25 December 2015 · mathsvault.uk/keystones
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1. Number Converting to standard form
Write 19,000,000 in standard form
Answer: 1.9 × 107 -
2. Algebra Factorising monic quadratics
Factorise: x² - 7x - 30
Answer: (x + 3)(x - 10) -
3. Geometry SOHCAHTOA — missing length
Adjacent = 17cm, angle = 39°. Find opposite. Give your answer to 2 decimal places
Answer: 13.77cm -
4. Ratio Mixed ratio problems
Simplify the ratio 5 litres : 850 ml
Answer: 100:17 -
5. Statistics Mean
The mean of 4 numbers is 28. If 3 of them are 24, 42, 24, what is the missing number?
Answer: 22