Hello, Quan!

We know this formula: . }" alt="\text{(Distance)} \:=\:\text{(Speed)} \times \text{}" />

Since the problem compares thetimesof the two vehicles,

. . we will use this variation: .

The average spped of an express train is 40km/h faster than the average speed of a bus.

To travel 1200km, the bus requires 50% more time than the train.

Determine the average speeds of the bus and the train.

Let: = speed of bus.

Then: = speed of train.

The train's speed is km/hr.

. . To travel 1200 km, it takes: hours.

The bus' speed is km/hr.

. . To travel 1200 km, it takes: hours.

We are told that the bus' time is 50% more than the train's time.

. . That is, it is: times the train's time.

There is our equation! . . . . .

Can you finish it now?