When you normally drive the freeway between Sacramento and San Francisco at an average speed of 105 km/hr (65 mi/h ), the trip takes 1.00 hr and 20 min . On a Friday afternoon, however, heavy traffic slows you down to an average of 90 km/hr (56 mi/h ) for the same distance. How much longer does the trip take on Friday than on the other days? (Express your answer in minutes to the nearest integer.)