If Sn denote the sum of the first n terms of an A.P. If S2n = 3Sn, then S3n : Sn is equal to

We know that Sn =


Now it is given that


S2n = 3Sn


= 3)


2(2n + 1) = 3(n + 1)


4n + 2 = 3n + 3


n = 1


now, S3n/Sn = ()


=


= 6

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