Series Question

Test Preparation
1

<p>When looking for the sum of the finite geometric series: 1+2+4+8+16 (2^(n-1)), I use the finite geometric sum formula, but it doesn't work.</p>

<p>I have S=1+2+4+8+16, S-2S=1-32,
S(1-2) = 1-32
S = (1-32)/(1-2)</p>

<p>This answer is double the real answer. Why is this so?</p>

2

<p>S = (1-32)/(1-2) = 31
1+2+4+8+16 = 31</p>

<p>How is it double the real answer?</p>

3

<p>Oops. lol. I don't know what I was thinking. I kept thinking 1-2 was .5...</p>

<p>I need to get some rest.</p>