Solve the problem .

(c) Consider two reaction vessels, one containing A and the other containing B, with equal concentrations at t = 0. If both substances decompose by first-order kinetics, where the rate constants are kA = 4.5 x 10-4 s -1 and kB = 3.70 x 10-3 s -1 , how much time must pass to reach a condition such that [A] = 4.00[B]?