Question

determine the sum of the first 6 terms of the geometric sequence where a=4 and r=2 the sum is__________.

Answer 1

The formula you need is:
$S_{n}=\frac{a(r^{n}-1)}{r-1}$
Plugging in the given values, we get:
$S_{6}=\frac{4(2^{6}-1)}{2-1}=252$