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If a(1), a(2), a(3),... are in AP such t...

If `a_(1), a_(2), a_(3)`,... are in AP such that `a_(1) + a_(7) + a_(16) = 40`, then the sum of the first 15 terms of this AP is

A

120

B

150

C

280

D

200

Text Solution

Verified by Experts

The correct Answer is:
D
`3a+6d+15d=40`
`3a+21d=40`
`a+7d=40/3`
`S_(15)=15/2(2a+14d)=15xx40/3=200`
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