Question

If a,b,c are in G.P., then $lo{g}_{a}n,lo{g}_{b}n,lo{g}_{c}n$ are in

• A. A.P.
• B. G.P.
• C. H.P.
• D. None

Answer 1

The correct option is C

H.P.

$b^2=ac\Rightarrow 2logb=loga+logc$
$\therefore lo{g}_{n}a,lo{g}_{n}b,lo{g}_{n}c$ are in A.P.
Their reciprocals $lo{g}_{a}n,lo{g}_{b}n,lo{g}_{c}n$ are in H.P.