Keystones — Capstone
Five GCSE retrieval questions · 2 August 2017 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √425
Answer: 5√17 -
2. Algebra Completing the square
Complete the square: x² - 11x - 9
Answer: (x - 11⁄2)² - 157⁄4 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 24cm, b = 24cm, angle = 72°. Give your answer to 2 decimal places
Answer: 273.9cm² -
4. Ratio Combining two ratios
a:b is 1:5 and b:c is 9:4. Find a:b:c in its simplest form.
Answer: 9:45:20 -
5. Statistics Averages and range
Find the mean, median and range of: 22, 37, 15, 87, 25, 50, 13, 54, 77. Give your answer to 2 decimal places
Answer: Mean = 42.22, Median = 37, Range = 74