Question

How many terms of the series

(a) 2 + 4 + 8 + …….makes the sum 1022

(b) 3 + 9 + 27 + ……. make the sum of 1092

(c) 2 + 6 + 18 + ……. make the sum 728

Answer 1

(a) The given series is

Here, and .

Thus, the first 9 terms of the given series make the sum 1022.

(b) The given series is

Here, and .

Thus, the first 6 terms of the given series make the sum 1092.

(c) The given series is

Here, and .

Thus, the first 6 terms of the given series make the sum 728.