6. A taxi driver picked up a fare at the Hyatt Regency Hotel who wanted to go to the airport. The traffic was heavy, and the taxicab’s average speed for the entire trip was just forty miles per hour. The total time of the trip was eighty minutes, and the customer was charged accordingly. At the airport, the taxi driver picked up another customer who wanted to be taken to the same Hyatt Regency Hotel. The taxi driver returned to the hotel along the same route that he had used just before, and traveled with the same average speed. But this time the trip took an hour and twenty minutes. Can you explain why?