CPM Homework Help : APCALC Problem 10-17

For each of the series below, decide if there is a finite sum. If there is a finite sum, predict the sum. If there is not a finite sum, explain why.

Hint:

For an infinite geometric series:

$S=\frac{a}{1-r}$

But $r$ must be _____.

More Help:

The series in part (a) is arithmetic.
The other series are geometric. What is the value of $r$ in each case?