Question: You normally drive on the freeway between San Diego and Los Angeles at an average speed of 91 km/h (57 mi/h), and the trip takes 2 h and 42 min. On a Friday afternoon, however, heavy traffic slows you down and you drive the same distance at an average speed of only 62 km/h (39 mi/h).
Part A: How much longer does the trip take?
Any help I can get on this question is greatly appreciated! I'm not too familiar with this problem.