Question

Find the sum of the geometric sequence 4, 16, 64, 256, 1024

Answer 1

4

Explanation:

The pattern is that each number is multiplied by 4 so the answer is 4. Oh this was 3 years ago.... raspberries!!

Answer 2

The formula for sum of a GP is

`S_n= (a_1(1-r^n))/(1-r)`
Where
`S_n` is the sum of 'n' terms,
`a_1` is the first term, 'r' is the common ratio
The common ratio is 16 divided by 4, that's 4


`S_(5)= (4(1-4^5))/(1-4)`

`S_(5)= 1364`