SOLUTION: A bus traveled 387 km in 5hrs. One hour of the trip was in city traffic. The bus’s speed was just half of its speed on open highway. The rest of the trip was an open highway. Find

Let R be the bus speed in the city, in km/h.

Then its speed in highway is 2r.


Moving 1 hour in the city, the bus covered r kilometers.

Moving the remaining 4 hours on the highway, the bus covered 4*(2r) = 8r kilometers.


The sum of the two distances is 387 kilometers.
It gives you an equation

r + 8r = 387  ====>  r =  = 43.


Answer.  The speed in the city was 43 km/h.