Question

A geometric series has a sum of 9,837. The common ratio is 3 and the first term is 9. How many terms are in the series?

Answer 1

\[s _{n} = \frac{a(r^{n}-1)}{r-1}\]
s = 9837
a = 9
r = 3
solve for n

Answer 2

use the formula

Sn = a * (r^n - 1)/ (r - 1)
n = no. terms r = common ratio and a = ist term

Answer 3

9?

Answer 4

7

Answer 5

dedfinitely 7 - sorry math must go