### Home > INT3 > Chapter 10 > Lesson 10.3.3 > Problem10-193

10-193.

What is the sum of the infinite series $324 + 54 + 9 + 1.5+ ...$ ? Homework Help ✎

Find the common ratio:

$\frac{54}{324}=\frac{1}{6}$

$\frac{9}{54}=\frac{1}{6}$

Use the equation for an infinite geometric series:

$\displaystyle\sum_{n=100}^{\infty}{ar^{n-1}}=\frac{a}{1-r}$