A bus traveled 387km in 5 hours. One hour of the trip was in city traffic. The bus's city speed was just half of its speed on open highway. The rest of the trip was on open highway. FInd the bus's city speed.

Let the bus's city speed be s.

For 1 hour, it travelled 1s km, or s km.

In the open highway, its speed was twice, hence 2s and it drove there for (5-1=) 4 hours and the distance is (2s x 4 =) 8s km.

These two distances add up to 387...

s + 8s = 387

Can you solve this?