Dominique drove home from work at an average speed of 36 miles per hour. If the distance from her house to her workplace is 5.4 miles, how long did her commute take?

distance = rate times time, so time = distance / rate.

Here,  time = length of commute = distance / rate = (5.4 miles) / (36 mph)      
                                                                               = 0.15 hour
                                                                                 = 9 minutes