Question

A passenger train and a freight train leave San Jose at 3PM, traveling in the same direction. The passenger train is going three times as fast as the freight train. At 6PM they are 240 miles apart. How fast is each travelling?

Answer 1

The passenger train is going 120MPH and the freight train is traveling 40MPH

Answer 2

Answer: The speed of the freight train = 40 miles per hour

And the speed of the passenger train =3(40)=120 miles per hour

Explanation:

Let the speed of the freight train be x miles per hour.

Then the speed of the passenger train is 3x miles per hour.

Time taken from 3PM to 6 PM= 3 hours

Since,
`\text{Distance=Speed}*\text{time}`

Now, The distance traveled by freight train=
`x*3=3x`

The distance traveled by passenger train=
`3x*3=9x`

Also, At 6PM they are 240 miles apart.

`\\\Rightarrow\ 9x-3x=240\\\Rightarrow\ 6x=240\\\Rightarrow\ x=(240)/(60)\\\Rightarrow\ x=40`

Thus, the speed of the freight train = 40 miles per hour

And the speed of the passenger train =3(40)=120 miles per hour