Determine whether the series is convergent or divergent. (1/3) + (1/6) + (1/9) + (1/12) + (1/15) ...

The given series (1/3) + (1/6) + (1/9) + (1/12) + (1/15) ... is an infinite geometric series. The geometric ratio from the series is 1/3. Hence the series is convergent because the ratio is less than 1. Convergent means the sum of the numbers of this series is a definite number because the numbers in the later orders become negligible then.