Trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 60 mph, train B is traveling at 70 mph. Train A passes the station at 10:15pm. If train B passes the same station at 10:45pm at what time will train B catch train A?

Question

Trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 60 mph, train B is traveling at 70 mph. Train A passes the station at 10:15pm. If train B passes the same station at 10:45pm at what time will train B catch train A?
__:__ (am/pm)
stuck on another one..word problems confuse me so bad..any help is greatly appreciated :)

drwls · Answer

Start measuring time from 10:45 AM. By that time, train A is 60 mph x 1/2 h = 30 miles ahead. The distance between the trains decreases at a rate 10 mph after that. The separation distance becomes zero after 30 miles/(10 miles/h) = 3 hours. B passes A at that time. Add three hours to 10:45 AM for the answer.