#1**+1 **

N =[Log(L/F) / Log(R)] + 1, where N=Number of terms, L=Last term, F=First term, R=Common Ratio.

N =[Log(512/2) / Log(2)] + 1

N = 9 - this is the number of terms. Then sum it up as Geometric Series:

First term =2

Common Ratio = 2

Number of terms =9

**You should get S = 1,022**

Guest Mar 6, 2018

edited by
Guest
Mar 6, 2018