Keystones — Capstone
Five GCSE retrieval questions · 13 December 2013 · mathsvault.uk/keystones
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1. Number Simplifying surds
Simplify: √525
Answer: 5√21 -
2. Algebra Completing the square
Complete the square: x² - 9x + 1
Answer: (x - 9⁄2)² - 77⁄4 -
3. Geometry Area using ½ab sin C
Find area of triangle: a = 25cm, b = 19cm, angle = 53°. Give your answer to 2 decimal places
Answer: 189.68cm² -
4. Ratio Combining two ratios
a:b is 4:5 and b:c is 2:9. Find a:b:c in its simplest form.
Answer: 8:10:45 -
5. Statistics Averages and range
Find the mean, median and range of: 55, 72, 78, 13, 81, 40, 42, 70, 50. Give your answer to 2 decimal places
Answer: Mean = 55.67, Median = 55, Range = 68