Keystones — Capstone
Five GCSE retrieval questions · 2 October 2015 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: 4√50
Answer: 20√2 -
2. Algebra Completing the square
Complete the square: x² + 7x + 7
Answer: (x + 7⁄2)² - 21⁄4 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 19cm, b = 15cm, angle = 78°. Give your answer to 2 decimal places
Answer: 139.39cm² -
4. Ratio Combining two ratios
a:b is 6:7 and b:c is 6:1. Find a:b:c in its simplest form.
Answer: 36:42:7 -
5. Statistics Averages and range
Find the mean, median and range of: 18, 13, 52, 92, 94, 12, 53. Give your answer to 2 decimal places
Answer: Mean = 47.71, Median = 52, Range = 82