[email protected] wrote: Train A leaves the station and travels at 30 miles per hour. Three hours later, train Ð’ leaves the same station traveling in the same direction at 40 miles per hour on a parallel track. How far from the station was train A overtaken by train B?
(A) 90
(B) 180
(C) 200
(D) 300
(E) 360

Train A leaves the station and travels at 30 miles per hour...for 3 hours
Train A/s travel distance = (rate)(time) = (30)(3) = 90 miles
So, at the moment, there's a 90 mile gap between the trains

then . . .

train Ð’ leaves the same station traveling in the same direction at 40 miles per hour on a parallel track.
Train B's speed is 10 miles per hour FASTER than Train A's speed.
So, the gap between them SHRINKS at a rate of 10 miles per hour.

We want to know the time it takes for the gap to shrink from 90 miles to 0 miles (a difference of 90 miles).

Time = distance/rate = 90/10 = 9 hours

How far does train B travel in those 9 hours?
Distance = (rate)(time) = [spoiler](40)(9) = 360 miles = E [/spoiler]

Cheers,
Brent