Question

How do you find the sum of the infinite geometric series 100+90+81+72.9+65.61...?

Answer 1

The sum of the infinite geometric series is `1000`.

Explanation:

This is a geometric series with first term as `100` and ratio of a term to its preceding term as `90/100=0.9`. As this ratio is less than `1`, the sum of the infinite geometric series is

`100/(1-0.9)=100/0.1=100xx10=1000`