Question

Marshall drove to work in rush hour traffic, going just 27 miles in 1 hour and 20 minutes. Later that day, he left work early to avoid the rush and was able to take the same route home in 29 minutes. What was Marshall's average speed overall? Write your answer as a whole number or as a decimal rounded to the nearest tenth.

Answer 1

The average speed of Marshall is 29.7 mph

Explanation:

Given;

distance traveled to work, d₁ = 27 miles

distance traveled back home, d₂ = 27 miles

initial time taken, t₁ = 1 hour and 20 minutes

final time taken, t₂ = 29 minutes

Total distance traveled, d = d₁ + d₂ = 27 miles + 27 miles = 54 miles

Total time taken for the journey, t = t₁ + t₂ = 1 hour + ( 20 mins + 29 mins)

t = 1 hour + 49 mins = 1 hour + 0.817 hour = 1.817 hour

The average speed is given by;

v = total distance / total time

v = 54 miles / 1.817 hour

v = 29.7 mph

Therefore, the average speed of Marshall is 29.7 mph