Question

Two trains leave the station at the same time, one heading west and the other east. the westbound train travels 10 miles per hour faster than the eastbound train. if the two trains are 400 miles apart after 2 hours, what is the rate of the westbound train?

Answer 1

Let
`w` be the speed of the westbound train,
`e` eastbound

Westbound is 10mph faster than eastbound:

w = 10 + e

After two hours, they're 400 miles apart:

400 = 2w + 2e

Solving,


`e = w-10`


`400 = 2w + 2(w-10) = 2w + 2w -20`


`420 = 4w`


`w=105` mph

That's the answer. That means the eastbound train is going 95 mph, so they're separating at 200 mph, so 400 miles apart after two hours. Check.