2018 · Q52
The arithmetic mean of two numbers is 10 and their geometric mean is 8. What are the two numbers?
Elementary MathematicsStatistics
- A15, 5
- B12, 8
- C16, 4
- D18, 2
Explanation
If the numbers are x and y: x + y = 20 and xy = 64. They are the roots of t² − 20t + 64 = 0, i.e. t = 16 and t = 4, option (C).