Find the common ratio of the geometric series with the sum and the first term Given: Geometric Series Sum ($S_n$) = 39
First Term ($a_1$) = 3
number of terms ($n$) = 3
Find the common ratio $r$.
*I have been made aware that the the common ratio is 3, but for anyone trying to solve this, don't plug it in as an answer the prove that it's true. Try to find it without using it.

Any way one can find the ratio, r, for higher powers i.e. where n=12, a1 =80 and the sum is 1200.
