Keystones — Capstone
Five GCSE retrieval questions · 6 February 2015 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: 2√28
Answer: 4√7 -
2. Algebra Completing the square
Complete the square: x² + 5x - 3
Answer: (x + 5⁄2)² - 37⁄4 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 21cm, b = 15cm, angle = 41°. Give your answer to 2 decimal places
Answer: 103.33cm² -
4. Ratio Combining two ratios
a:b is 9:4 and b:c is 3:2. Find a:b:c in its simplest form.
Answer: 27:12:8 -
5. Statistics Averages and range
Find the mean, median and range of: 21, 18, 31, 27, 22, 88, 25, 15. Give your answer to 2 decimal places
Answer: Mean = 30.88, Median = 23.5, Range = 73