Respuesta :
Answer:
Time spent on the greenway road = 4.5 hours
Time spent on the 2 lane road = 1.5 hours
Explanation:
The distance of the trip is 360 miles and the initial speed of the car is 62 miles/hr and after the road became 2 lane highway the car slowed to 54 miles/hr.
Let us divide the trip into two
Greenway
speed = distance/time
speed = 62 mph
time = a
distance = speed × time
distance = 62a
2 lane highway
speed = distance/time
speed = 54 mph
time = b
distance = speed × time
distance = 54b
Total distance
62a + 54b = 360......................(i)
Total time
a + b = 6..............................(ii)
a = 6-b
insert a in equation (i)
62(6-b) + 54b = 360
372 - 62b + 54b = 360
-8b = 360-372
-8b = - 12
b = 12/8
b = 1.5
from equation (ii)
a + 1.5 = 6
a = 6 - 1.5
a = 4.5
