If a,b,c are in GP,Which of the following will be the common ratio of the GP.
If the common ratio is r,
b=ar
c=ar2
⇒ ba = r, ----------(A)
ca = r2
⇒ (ca)12 = r,--------------(B)
cb = ar2ar
⇒ cb = r, ----------(C)
c−bb−a=ar2−arar−a=r(ar−a)(ar−a)
= r -------------------------(D)