Download the app

Questions  

 If ar>0,rN and a1,a2,a3.a2n are A.P. then a1+a2na1+a2+a2+a2n1a2+a3+a3+a2n2a3+a4+..+an+an+1an+an+1=

Remember concepts with our Masterclasses.

80k Users
60 mins Expert Faculty Ask Questions
a
n-1
b
na1+a2na1+an+1
c
n−1a1+an+1
d
1

Ready to Test Your Skills?

Check Your Performance Today with our Free Mock Tests used by Toppers!

detailed solution

Correct option is B

a1+a2n=a2+a2n−1......=K (say) a1+a2na1+a2+.......+an+an+1an+an+1=Ka1−a2a1−a2+….+an−an+1an−an+1                                                         =−Kda1−an+1a1+an+1   Where d=a1−a2=…..=an−an−1                                                         =na1+a2na1+an+1


Similar Questions

If the sum of first n terms of an AP is cn2, then the sum of squares of these  n terms is 


whats app icon
phone icon