Question

at 1:30 in the afternoon an old freight train and a new dart express train pull out of the new garland station going in opposite directions the dart express train goes three times faster than the hold freight train. fifteen minutes later the two trains are already 30 miles apart find the speed of each train?

Answer 1

`V_(E) = -22.5 / 15 = 1.5 miles/minute\\V_(F) = 7.5 / 15 = 0.5 miles/minute`

Explanation:

To answer this problem, we must bear in mind that the express train travels 3 times faster than the freight train.

If we call F the distance that the freight train travels and we call E at the distance that the express train travels, we must have the distance between them after 15 minutes it must be 30 miles.

So

`F + E = 30\\`

We also know that:

`E = 3F`

Since the express train travels 3 times faster than the freight train.

So, like both equations, we have to:

`F + 3F = 30\\F = 30/4\\F = 7.5 miles\\`

Then
`E = 7.5*3 = 22.5` miles in the opposite direction.

This is the distance you traveled in 15 minutes.

Therefore, the speed of the express train (
`V_(E)`) is the distance traveled between the time it did

`V_(E) = -22.5 / 15 = 1.5 miles/minute\\V_(F) = 7.5 / 15 = 0.5 miles/minute`