Two trains leave towns 845 miles apart at the same time and travel toward each other. One train travels 19 mi/h slower than the other. If they meet in 5 hours, what is the rate of each train?
Perhaps we can introduce a variable, d, for the distance(over 1 hour). Assume d/1 hour is the speed of the faster train, which means that (s-19)/ 1 hour is the speed of the second(in miles/hour, of course). The total distance covered in 1 hour is d+d-19 = 2d-19. 5 hours becomes 5(2d-19) , which equals 845 since they meet. 845/5 = 169. 2d -19 = 169 =>> 2d = 188 ==> d = 188/2 = 94.
The speed of the faster train is 94 miles/hour and the slower one is 94-19 = 75 miles/hour. I hope this is the answer. Look over it, and if you need help understanding, ask!