(Q12).Which of the following lists of numbers form GP?

(i) 3, 6, 12, .....

(i)We know that a list of numbers a1 , a2 , a3 , .....an ..... is called a GP if each term is non zero and
a2
a1
 =
a3
a2
 = ......
an
an-1
 = r

Here all the terms are non zero. Further

a2
a1
 =
= and
a3
a2
 =
=
i.e.,
a2
a1
 =
a3
a2
 =

So, the given list of number forms a GP with the common ratio .