In the series 2, 6, 18, 54, ...... what will be the 8th term ? (1) 4370 (2) 4374 (3) 7443 (4) 7434
Explanation: Clearly, 2 x 3 = 6, 6 x 3 = 18, 18 x 3 = 54,..... So, the series is a G.P. in which a = 2, r = 3. Therefore 8th term = ar8-1 = ar7 = 2 x 37 = (2 x 2187) = 4374.