Respuesta :
Average speed = (total distance) / (total time).
Total distance = (100 miles + 30 miles + 75 miles) = 205 miles
Total time = (2 hours + 1 hour + 1 hour) = 4 hours
Average speed = (205 miles) / (4 hours) = 51.25 miles/hour
Rounded to the nearest whole number, that's 51 mph .