Question

What is the sum of the first seven terms of the geometric series? 3 + 12 + 48 + 192 + ... 4,372 12,288 16,383 65,535

Answer 1

Answer:

16,383 or C

Step-by-step explanation:

Answer 2

Answer:

Option 3rd is correct.

Step-by-step explanation:

Given: 3 + 12 + 48 + 192 + .......

We have to find : Sum of first seven term of the given Geometric series.

First term , a = 3

Common ratio , r = $\frac{12}{3}=4$

Sum of the n term of series,  $S_n=\frac{a(1-r^n)}{1-r}$

So,

$S_7=\frac{3(1-4^7)}{1-4}$

$S_7=\frac{3(1-4^7)}{-3}$

$S_7=-(1-16384)$

$S_7=-(-16383)$

$S_7=16383$

Therefore, Option 3rd is correct.