physics
posted by Anonymous on .
Sally travels by car from one city to another. She drives for 30.0 min at 80 km/h, 12 min at 105 km/h, and 45 min at 40 km/h. She spends 13.0 min eating lunch and buying gas. what the average speed for the trip?

averagespeed=total distance/totaltime
Total time=.5+12/60+45/60+13/60
total distance: figure each (time*speed), and add.