Question

It takes eight hours for a 600 km journey. if 120 km is done by train and the rest by car. It takes 20 min more if 200 km is done by train and the rest by car. The ratio of the speed of the train to that of the cars is

Options

• 2 : 3

• 3 : 2

• 3 : 4

• 4 : 3

Answer 1

3 : 4
Explanation:
Let the speeds of the train be x km/h and that of the car be y km/h.

Then, `120/x+480/y=8`

⇒ `1/x+4/y=1/15`                ...(i)

and `200/x+400/y=25/3`

⇒ `1/x+2/y=1/24`               ...(ii)

On solving Eqs. (i) and (ii), we get
x = 60 and y = 80
∴ Ratio of speeds = 60 : 80 = 3 : 4