Question

The sum of 7 terms of the G.P. 3, 6, 12, ........... is ______.

Options

• 181

• 241

• 381

• 421

Answer 1

The sum of 7 terms of the G.P. 3, 6, 12, ........... is 381.

Explanation:

Here, $$a = 3$$ and $$r = 2$$.

Therefore, $$S_7 = \frac{3(2^7 - 1)}{2 - 1} = 3 \times 127 = 381$$.