A car travels 60 miles with a constant speed of 57 mph and then another 60 miles with 40 mph. How long
 does it take for the car to travel the first 60 miles?
 t₁ =
 What time is required to travel the second 60 miles?
 Units hrs
 t₂ =
 Units hrs
 What is the average speed of the car for the entire trip?
 The average speed, v =
 Units mph