Substitute the given number in your formula and solve for the remaining variable. .. 300 = 100e^(0.7t) .. 3 = e^(0.7t) . . . . . . . . . divide by 100 .. ln(3) = 0.7t . . . . . . . . . .take the natural logarithm .. ln(3)/0.7 = t . . . . . . . . . divide by the coefficient of the variable .. 1.6 = t
