Sequence And Series Question 96
Question: a, b, c, d, $ \in {R^{+}} $ such that a, b, and c are in A.P. and b, c and , d are in H.P., then
Options:
A) ab = cd
B) ac = bd
C) bc = ad
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ 2b=a+c,c=\frac{2bd}{b+d} $
$ \Rightarrow 2bd=c(b+d) $
$ \Rightarrow (a+c)d=c(b+d) $ $ [as2b=a+c] $
$ \Rightarrow ad+cd=bc+cd $
$ \Rightarrow bc=ad $
BETA
