Question 295496
Let the speed of the express bus = x mph
Then, the speed of the local bus = x-15 mph
Given, the local bus finishes its 50-mile route in the same amount of time that an express bus finishes its 75-mile route
So, 50/(x-15) = 75/x
50x = 75(x-15)
50x = 75x-1125
1125=75x-50x
25x = 1125
x = 1125/25
x = 45 mph
x-15 = 45-15 = 30 mph
So, the speed of the express bus = 45 mph
and the speed of the local bus = 30 mph
Time taken to travel the route = 75/45 = 5/3 hours = 1 h 40 min