Infinite geometric series

S∞= a/1-r                    a=7,  r=0.2 or 1/5        3, 3/5, 3/25, 3/125…..

S∞=7/1-1/5

S∞=7÷4/5

S∞=35/4

This week , I learn Infinite Geometric Series. An infinite geometric series has an infinite number of terms. To determine the sum of an infinite geometric series, we need to know a, a is the t1. Common ratio is -1 < r < 1 . The sum of the series, S∞ is : S∞=a/1-r