SOLUTION
From the series given below
100, 90, 81, 72.9
You noticed you were right when you said the common ratio r = 0.9
Suh a series oconverges. This is because the common ratio r is less than 1.
So when a series has r < 1, as seen in this type, it is said that such as series converges. And hence we ca find the sum to infinity of such series given as
[tex]\begin{gathered} S=\frac{a}{1-r} \\ Where\text{ S is the sum to infinity, a the first term and r the common ratio } \end{gathered}[/tex]
