Average speed = Distance/ time
Distance = 180 mi
Time = time(final) - time(initial)
To find time will be easier if we translate am and pm into 24 h scale.
am will stay the same, so 10:30 am is 10:30. (initial)
pm will be turned (am time + 12), 3: 00 pm = 3:00 +12 =15:00 (final)
Time = time(final) - time(initial)= 15:00 - 10:30 = 14:60 - 10:30 =4h 30 min
4h + 30 min = 4h + 1/2 h= 4.5 h (time)
Average speed = Distance/ time = 180 mi / 4.5 h = 40 mi/h
Answer is 40 mi/h.
