The sum of a geometric series with a=2 r=3 and 4 terms is?
A
80
B
90
C
100
D
110
Correct Answer: Option A — 80
Explanation:
Sum = a(rⁿ-1)/(r-1) = 2(3⁴-1)/(3-1) = 2(80)/2 = 80. The finite geometric series formula applies when r≠1. For infinite series with |r|<1 sum = a/(1-r). Geometric series appear in competitive exam sequences and progressions sections and in financial problems involving compound growth scenarios.