Question

Find the common ration of a G.P. that has a first term of 5 and sum to infinity of 15.

Answer 1

any thoughts on how to proceed?

Answer 2

Sum to Infinity terms of a GP is given as:

\[Sum = \frac{a}{1-r}\]

Here, you are given with Sum and first term (a).. Try to find r which is your common ratio.. :)