If series is `1, sqrt3 , 3 ---`, then find which term is 81

The sum of the terms of an infinite geometric progression is 3 and the sum of the squares of the terms is 81. Find the first term of the series.

if sqrt(3^(n))=81 then n=

The nth term of a series is 3^(n)+2n; find the sum of first n terms of the series.

Find the number of terms in the series 20,19(1)/(3),18(2)/(3)... the sum of which is 300. Explain the answer.

Z_1, Z_2, Z_3, ........... are terms of an A.P with common difference(1-i sqrt 3) and one of the term of A. P. being 1. omega_1,omega_2,omega_3.... are terms of a G.P. with common ratio (1+i sqrt3) and first term being 1