Question

Calculate s7 for the series 3,9,27

Answer 1

the sumatory of a geometric sequence is given by the following equation:

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

In this case, we have a geometric sequence with first term 3, common ratio 3, and the number of terms 7, thus, we get:

`S_7=(a(r^n-1))/(r-1)=(3(3^7-1))/(3-1)=3279`

So that, we can conclude that the correct answer is:

`3279`