Which of the following sequences are in G.P.? (ii) 4,44,444,4444,...

Which of the following sequences are in G.P.?

(ii) 4,44,444,4444,...

Solution :

First term (a)  = 3, common ratio

r  = t2/t1   =  44/4 r = 11

r  = t3/t2   =  444/44 r = 111/11

r  = t2/t1   =  4444/444 r = 1111/111

Since the common ratios are not same, it is not geometric sequence.