Question

How do you find the sum of the following infinite geometric series, if it exists 3 + 9 + 27 + 54 +…?

Answer 1

`a_2/a_1=9/3=3`

`a_3/a_2=27/9=3`

`implies` common ratio`=r=3`

Since the common ratio is greater than, therefore, the series is divergent and hence it's sum can not be found. However, its sum can be said to be infinite.