Question

How do you find the sum of the infinite geometric series 1/2 + 1/10+ 1/50+ 1/250+ ... ?

Answer 1

Use the formula `a_1 / (1-r)` where `|r|<1`

Explanation:

Just use the formula given, in this case `a_1 = 1/2` and
`r=1/5`

So by substituting in the formula

We will have `SUM = 1/2/(1-1/5)`
`SUM= 1/2/4/5`
`SUM=5/8`