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The 15th term of the series 2 1/2+1 7/(1...

The 15th term of the series `2 1/2+1 7/(13)+1 1/9+(20)/(23)+..` is

A

`10/39`

B

`10/21`

C

`10/23`

D

none of these

Text Solution

Verified by Experts

The correct Answer is:
A
Reciprocals of the terms of the series are 2/5,13/20,9/10,23/20,…. Or 8/20,13/20,… Its nth term is
`(8+(n-1)5)/20=(5n+3)/20`
Therefore, the 15th term is `20/78=10/39`.
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