On a trip, Duke encounters some road construction that slows him down. While he is able to go 60 mph on the highway and 40 mph through cities, he can only go 20 mph past the construction. He spends half the time on the highway as he does in construction, so the 380-mile trip takes 11 hours. How much of this time does he spend on the highway, in the city, and through road construction? what are the 3 variables