Question

Find the harmonic mean, if arithmetic mean is 27 and geometric mean is 9 ?
1. 9√3
2. 9 
3. 3
4. 27

Answer 1

Correct Answer - Option 3 : 3

Concept:

The relation between AM, GM and HM:

(GM)2 = (AM) × (HM)

 

Calculation:

Given AM = 27 and GM = 9

And we know that (GM)2 = (AM) × (HM)

⇒(9)² = 27 × HM

⇒ HM = \(\frac{81}{27}\)

= 3  

Hence, option (3) is correct.