Q: What represents the sum of a geometric series with 8 terms whose first term is 3 and common ratio is 4.

A: 65,535

Is my answer right? I wasn't sure when adding up the terms versus using Sigma notation.

How about just using the formula for Sn of a geometric sequence?

3(4^8-1)/(4-1) = 4^8-1 = 65535

To find the sum of a geometric series, you can use the formula:

S = a * (r^n - 1) / (r - 1)

where S represents the sum of the series, a represents the first term, r represents the common ratio, and n represents the number of terms.

In this case, the first term (a) is 3, the common ratio (r) is 4, and we have 8 terms, so n = 8.

Plugging these values into the formula:

S = 3 * (4^8 - 1) / (4 - 1)
= 3 * (65,536 - 1) / 3
= 3 * 65,535 / 3
= 65,535

So, your answer of 65,535 is correct.