Home » Blog » Prove that the sum from 1 to ∞ of 2 / 3n-1 = 3 Prove that the sum from 1 to ∞ of 2 / 3n-1 = 3 by RoRi February 29, 2016 Prove that the following sum converges and has the given value. Here we use the formula for a geometric series, Related