If the ratio of the sum of the first 6 terms of a G.P. to the sum of the first 3 terms of the G.P. is 217, what is the common ratio of the G.P?  Choose the correct option.
A) 3
B) 1/3
C) 2
D) 6
E) 1/6
217=(a1+a2+a3+a4+a5+a6)/(a1+a2+a3)   Factorize the same terms   217=1+(a4+a5+a6)/(a1+a2+a3)   Write every term with respect to r   a1=a1   a2=a1*r^1   a3=a1*r^2   .........   217=1+(a1(r^3+r^4+r^5))/(a1(1+r^1+r^2))   216=(r^3 (1+r^1+r^2))/((1+r^1+r^2))   216=r^3   r=6   6
<result>D</result>
If the ratio of the sum of the first 6 terms of a G.P. to the sum of the first 3 terms of the G.P. is 217, what is the common ratio of the G.P?