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Consider an A. P .a1,a2,a3,..... such th...

Consider an `A. P .a_1,a_2,a_3,.....` such that `a_3+a_5+a_8 =11and a_4+a_2=-2` then the value of `a_1+a_6+a_7` is.....

A

-8

B

5

C

7

D

9

Text Solution

Verified by Experts

The correct Answer is:
C
Given that
`a_(3)+a_(5)+a_(8)=11`
`rArra+2d+a+4d+a+7d=11`
or 3a+13d=11
Given,
`a_(4)+a_(2)=-2`
`rArra+3d+a+d=-2`
or a=-1-2d
Putting value of a form (2) in (1), we get
`3(-1-2d)+13d=11`
`rArr7d=14`
`rArrd=2anda=-5`
`rArra_(1)+a_(6)+a_(7)=7`
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