Consider the series $82 – 24.6 + 7.38 – 2.214 + …$ .

1. What is the sum of the first $12$ terms of the series?

   Hint (a):

   $r=-\frac{24.6}{82}$

   More Help:

   See the Math Notes box in Lesson 10.3.1 for the formulas for the sum of geometric series.

2. What is the infinite sum?

   Answer (b):

   $S=\frac{82}{1-(-0.3)}\approx 63.077$