Question

The first term in a geometric series is 5 and the common ratio is 2.

Find the sum of the first 10 terms in the series.

Answer 1

5115

Explanation:

The sum to n terms of a geometric series is

`S_(n)` =
`(a(r^n-1))/(r-1)`

where a is the first term and r the common ratio

Here a = 5 and r = 2, thus

`S_(10)` =
`(5((2)^(10)-1) )/(2-1)` = 5 × (1024 - 1) = 5 × 1023 = 5115