What is the sum of the first five terms of a geometric series with a1 = 6 and r = 1/3?

The sum of the terms of a geometric sequence with common ratio lesser than 1 is calculated through the equation,

Sn = (a1) x (1 - r^n) / (1 - r)

Substituting the known values,

S5 = (6) x (1 - (1/3) ^5) / (1 - 1/3) = 242/27

Thus, the sum of the first five terms is approximately equal to 8.96.