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If the sequence {S(n)} is a geometric pr...

If the sequence `{S_(n)}` is a geometric progression and `S_(2)S_(11)=S_(p)S_(8)`, then what is the value of p ?

A

1

B

3

C

5

D

cannot be determined

Text Solution

Verified by Experts

The correct Answer is:
C
Given `S_(2)S_(11)=S_(P)S_(8)`
`implies" "(ar)(ar^(10))=ar^(p-1)(ar^(7))`
where 'a' is the first term and 'r' is the common ratio of G.P.
`impliesr^(11)=r^(7+p-1)impliesr^(11)=r^(6+p)`
`implies11=6+pimpliesp=5`
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