2020 · Q100
The harmonic mean and the geometric mean of two numbers are 10 and 12 respectively. What is their arithmetic mean?
Elementary MathematicsStatistics
- A25/3
- B√20
- C11
- D14.4
Explanation
AM = GM^2/HM = 144/10 = 14.4. Hence option (D). For two positive numbers AM*HM = GM^2 always, so AM = 144/10 = 14.4 directly.