Keystones — Capstone
Five GCSE retrieval questions · 14 September 2014 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √405
Answer: 9√5 -
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 = 25cm, b = 23cm, angle = 51°. Give your answer to 2 decimal places
Answer: 223.43cm² -
4. Ratio Combining two ratios
a:b is 5:9 and b:c is 8:3. Find a:b:c in its simplest form.
Answer: 40:72:27 -
5. Statistics Averages and range
Find the mean, median and range of: 28, 95, 46, 61, 81, 19, 85, 25, 21. Give your answer to 2 decimal places
Answer: Mean = 51.22, Median = 46, Range = 76