Find the least value of n for which the sum 1 + 3 + 32+ ...... to n terms is greater than 7000.
The ratio of the sum of first three terms is to that of first 6 terms of a G.P. is 125 : 152. Find the common ratio.
If S1, S2 and S3 be respectively the sums of n, 2n and 3n terms of a GP., prove that S1 (S3 – S2) = (S2 – S1)2
Let a be the first term and r be the common ratio of a G.P.
                                                        ...(i)
                                                          ...(ii)
                                                ...(iii)
L.H.S. =
        =
R.H.S. =
           =
∴  L.H.S. = R.H.S.
Hence,    Â
Let S be the sum, P the product and R the sum of the reciprocals of n terms in a G.P. Prove that