Answer:
Time taken by Duke on the highway = 3 hours
Time spent on the construction = 6 hours
Time spent in the city = 2 hours
Step-by-step explanation:
Speed by which Duke travels a distance on highway = 60 mph
Let the time taken to travel on highway = hours
Distance traveled = miles
Speed in the city = 40 mph
Let the time taken = hours
Distance traveled in the city = miles
Speed on the construction = 20 mph
Let the time spend on the construction = hours
Distance traveled on the construction = miles
Since, total distance covered = 380 miles
He spends one half the time on the highway as he does on the construction,
Total time spent in the trip = 11 hours
Therefore,
From equation (1),
hours
hours
hours
Therefore, time taken by Duke on the highway = 3 hours
Time spent on the construction = 6 hours
Time spent in the city = 2 hours