Question

Find the sum of the series 1 + 1/3 + 1/9 + ... + 1/3k-1 + ...

Answer 1

Its a G.P

Answer 2

This is a geometric sequence of the form ar^n, where a is the first term and r is the number you multiply each term by to get the next term. The sum of a geometric series, if -1<r<1, is a/(1-r). Find r and a for this sequence, then plug in.