a) The formula for calculating the distance is expressed as
distance = speed x time
From the information given,
speed = 65 mi/h
time = 1 hour and 30 minutes = 1.5 hors
Distance = 65 x 1.5
Distance during this time = 97.5 miles
b) Recall,
Total distance = 100 miles
Distance covered in the last part of the trip = 100 - 97.5 = 2.5
Time = half-hour = 0.5
Speed = 2.5/0.5 = 5
the average speed during this leg of the trip = 5 mi/h
c) average speed = total distance/ total time
total time = 1.5 + 0.5 = 2 hours
total distance = 100
average speed = 100/2 50
Average speed for the total trip is 50 mi/h