A cab driver drives

Question

a cab driver drives from the airport to a passengers home at an average speed of 60 miles per hour. After the pickup, the cab driver returns with the passenger along the same route to the airport at an average speed of 45 miles per hour. The roadtrip takes 2.1 hours. What is the drivers average speed throughout the trip? Round your answer to the nearest hundredth.

Answer 1

distance = rate of speed times time traveled

d = rt

for one way it's

d= 60t and coming back

d = 45(2.1-t)

d is the same each way so

60t= 45(2.1-t) = 94.5 - 45t

105t = 94.5

t = 94.5/105 = 18.9/21 = 6.3/7 hours= 0.4286 hours

2.1-t = 1.7714 hours for the return trip at slower speed

distance one way = 60 x 6 3/7 = 360/7

for both ways, total distance = 2 x 360/7 = 720/7

average speed for round trip = total distance/2.1

= 720/7 divided by 2.1

=720/14.7 = close to 49 mph or about 48.98 mph