# Thread: I'm stuck on this series as well :(

1. ## I'm stuck on this series as well :(

Question:

Determine:
(a) whether is convergent.
(b) whether is convergent.

All I know to do is 10 * (5/5^n) and then I'm stuck and I'm not even sure that I am on the right track or if what I did is absolutely pointless.

Any help would be greatly appreciated!
Thanks in advance!

2. Originally Posted by s3a
Question:

Determine:
(a) whether is convergent.
(b) whether is convergent.

All I know to do is 10 * (5/5^n) and then I'm stuck and I'm not even sure that I am on the right track or if what I did is absolutely pointless.

Any help would be greatly appreciated!
Thanks in advance!
You can use ratio test to check if the series converges. Try using Ratio test and show where you get stuck.

3. That is a simple geometric series with $a=10~\&~r=\frac{1}{5}$.