Question

What is the sum of the geometric sequence 2,8,32,... if there are 8 terms? Answers to choose from.

a)21,845
b)43,690
c)65,535
d)87,380

Answer 1

Do you know the formula for the sum of \(n\) terms in a geometric sequence?

Answer 2

no could you guide me through this whole problem

Answer 3

\[\Large{S_{n} = \frac{a_{1}(1-r^{n})}{1-r}}\]
\(a_{1}\) is your first term.
\(r\) is the ratio (what you multiply by between each term).
\(n\) is the number of terms (given as 8).

Answer 4

ok

Answer 5

i got 43,690 as my answer is this correct?

Answer 6

That's what I get.

Answer 7

thankyou

Answer 8

No problem.