SOLUTION: The average speed of an express train is 40 km/h faster than the average speed of a bus. To travel 1200km, the bus requires 50% more time than the train. Determine the average sp

Let B be average speed of the bus, in kilometers per hour.

Then the average speed of the train is (B+40) km/h, according to the condition.


The bus covers 1200 km in  hours.
The train covers 1200 km in  hours.

The condition says that to travel 1200 km, the bus requires 50% more time than the train. It means that

 = .

It is your equation to find the unknown B.


Simplify it step by step, first canceling 1200 in both sides:

 =   ---->

B + 40 = 1.5*B  (after cross multiplying)  ---->

0.5B = 40  ---->  B =  = 80 km/h.


Thus the bus speed is 80 km/h.

Then the train speed is (B+40) = 80 + 40 = 120 km/h.


Check.  Bus' time = {{1200/80}}} = 15 hours.

        Train's time =  = 10 hours.


Answer.  The bus' speed = 80 km/h.  The train' speed = 120 km/h.

              SPEED       TIME       DISTANCE 

TRAIN          r+40       t            1200

BUS            r          t+t/2        1200