Multiple choice Find the sum of the first $8$ terms of the geometric series if $a_1=2$ and $r = 2$. $210$ $310$ $410$ $510$ Reveal answer Fill a bubble to check yourself D Correct answer Explanation Sum of GP = a(r^n - 1) / (r - 1). a = 2, r = 2, n = 8. Sum = 2(2^8 - 1) / (2 - 1) = 2(256 - 1) = 2 * 255 = 510.