Question

Find the value of `a_1`, for an infinite geometric series with `S=12` and `r=1/6`?

Answer 1

`10`.

Explanation:

For the infinite Geom. Series, we have, `S=a_1/(1-r), |r| <1`.

`:. a_1/(1-1/6)=12`.

`rArr a_1=12*5/6=10`.