A chemical engineer wants to design a continuous stirred tank reactor (CSTR) with a volume of 50 liters. The flow rate of reactant A into the reactor is 0.2 m^3/min and the reaction rate is given by the equation: -rA = kC_A^2 where k = 0.15 min^-1 and C_A is the concentration of reactant A in mol/L. The reactor is well mixed and the concentration of reactant A is uniform throughout the reactor. Determine the residence time of the reactor.