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put this solution on YOUR website! The formula for Maturity Value (Principal plus interest) for simple interest is M = P(1+rt). In this case, M=3P - we want to triple our original investment.
3P=P(1+.06t)
3 = 1+.06t
3-1 = .06t = 2
t = 2/.06 = 33.333.... = 33 and 1/3 years.