Q56 of 74 Page 9

Show that the ratio of the sum of first n terms of a G.P. to the sum of terms from (n+1)th to (2n)th term is 1/rn.


Consider the G.P. a, ar, ar2,…….

Sn =

Sum of terms from (n + 1)th to (2n)th terms

    = S2n - Sn

    =

Now Required ratio =
                           =

                           =

                           =

                           =

                           = = R.H.S.

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