SOLUTION: The ratio of the sum of the first three terms of a G.P to the sum of the first 6 terms is 27:19. The common ratio is 2/3 -2/3 -1.5 1.5

   +  +  +  +  +  = 


=  =  +  = .


Therefore,


 =  = .


Hence,    =    and   =  = .


It implies   r =  = .


Answer.  r = ,  which is the  first line of the option's list.