Question

To travel 432 km, an Express train takes 1 hour more than Duronto. If however, the speed of the Express train is increased by 50%, it takes 2 hours less than Duronto. What is the speed (in km/hr) of Duronto train?

Answer 1

To travel 432 km, an Express train takes 1 hour more than Duronto. If however, the speed of the Express train is increased by 50%, it takes 2 hours less than Duronto. What is the speed (in km/hr) of Duronto train

Answer 2

Answer:

54 km/hr

Step-by-step explanation:

Let the speed of Duronto train be y km/hr and that of Express train be z km/hr

According to the problem statement

⇒ 432/y + 1 = 432/z

⇒ 1/z = 1/y + 1/432        ----(i)

If speed of Express train increased by 50%, now the speed will be 1.5 z,

Now

⇒ 432/1.5z + 2 = 432/y Using (i)

⇒ 288(1/y + 1/432) + 2 = 432/y

⇒ 288/y + 2/3 + 2 = 432/y

⇒ y = 54 km/hr

∴ the speed of Duronto train is 54 km/hr