_____ The population can be given by p(n) = p₀×1.064ⁿ . . . . where n is the number of hours You want to find n whe p(n) = 2*p₀. 2p₀ = p₀×1.064ⁿ . . . . . . . . . . . . substitute the given information 2 = 1.064ⁿ . . . . . . . . . . . . . . . . . divide by p₀ log(2) = n×log(1.064) . . . . . . . . take logs to make it a linear equation log(2)/log(1.064) = n . . . . . . . . divide by the coefficient of n