Question

1/3 + 1/9 + 1/27 + 1/81 + 1/243 + ...

Answer 1

This kind of series has a name and known properties. Identification is the first, most important part. What kind of series is it?

Answer 2

it looks like a geometric sequence

Answer 3

That was my impression.

Normally:

'a' is the first term and
'r' is the common ratio.

Can you identify those parts?

Answer 4

a=1/3 and r = 1/3

Answer 5

That's it. Now what's the sum of such an infinite series?