Sequence And Series Question 630
Question: If s is the sum of an infinite G.P., the first term a then the common ratio r given by
[J & K 2005]
Options:
A) $ \frac{a-s}{s} $
B) $ \frac{s-a}{s} $
C) $ \frac{a}{1-s} $
D) $ \frac{s-a}{a} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ s=\frac{a}{1-r} $
Þ $ s-sr=a $
Þ $ -sr=a-s $
Þ $ r=\frac{s-a}{s} $ .
BETA
