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Question: Answered & Verified by Expert
If a1,a2,a3.........,an are in A.P. and a1+a4+a7.........+a16=114 , then a1+a6+a11+a16 is equal to :
MathematicsSequences and SeriesJEE MainJEE Main 2019 (10 Apr Shift 1)
Options:
  • A 64
  • B 98
  • C 38
  • D 76
Solution:
2678 Upvotes Verified Answer
The correct answer is: 76

We know that sum of equidistant term from end & beginning is same in any A.P. a1+a16=a2+a15=a3+a14=a4+a13=a5+a12==a7+a10

 a1+a4+a7+a10+a13+a16=114

3a1+a16=114a1+a16=38

Then,

a1+a6+a11+a16

=2a1+a16=76

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