Question

What is the sum of the geometric sequence 1, 3, 9, if there are 11 terms?

Answer 1

The answer is 88,573

Answer 2

Answer:

The sum of GP series is 88573

Step-by-step explanation:

Given the geometric sequence

1, 3, 9,...  11 terms

we have to find the sum of 11 terms.

a=1, r=3, n=11

The formula for finite terms of GP is

$S_n=\frac{a(1-r^n)}{1-r}$

$=\frac{1(1-3^{11})}{1-3}=\frac{177146}{2}=88573$

The sum of GP series is 88573