If each term of an infinite G.P. is twice the sum of the terms following it, then the common ratio of the G.P. is
The sum of an infinite G.P. is 4 and the sum of the cubes of its terms is 192. The common ratio of the original G.P. is
Show that in an infinite G.P. with common ratio r(|r|<1), each term bears a constant ratio to the sum of all terms that follow it.