Sequence And Series Question 320

Question: The harmonic mean between two numbers is and the geometric mean 24. The greater number them is

[UPSEAT 2004]

Options:

A) 72

B) 54

C) 36

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

Let two number $ a $ and $ b $ We know that $ H=\frac{G^{2}}{A}\Rightarrow \frac{72}{5}=\frac{576}{A} $
$ \Rightarrow $ $ A=40 $ $ a+b=80 $ ?..(i) and $ ab=576 $ $ a-b=64 $ ?..(ii) On solving equation (i) and equation (ii), $ a=72 $ , $ b=8 $ Maximum Number 72.