Sequence And Series Question 267
Question: If A.M. of two terms is 9 and H.M. is 36, then G.M. will be
[RPET 1995]
Options:
A) 18
B) 12
C) 16
D) None of the above
Show Answer
Answer:
Correct Answer: A
Solution:
(A.M.) (H.M.) $ =ab={{(G.M)}^{2}} $
$ \Rightarrow $ $ 9\ .\ 36={{(G.M)}^{2}} $
$ \Rightarrow $ $ =\frac{n(n+1)(3n^{2}+7n+2)}{12} $ .
BETA
