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The fifth term of an AP of n terms, whos...

The fifth term of an AP of n terms, whose sum is `n^2 -2n`, is

A

5

B

7

C

8

D

15

Text Solution

Verified by Experts

The correct Answer is:
B
Given, `S_(n)=n^(2)-2n.`
We know, `T_(n)=S_(n)-S_(n-1)`
So, `T_(5)=S_(5)-S_(4).`
`S_(5)=5^(2)-2(5)=25-10=15`
`S_(4)=4^(2)-2(4)=16-8=8`
So, `T_(5)=15-8=7.`
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