Posted by Samantha on Wednesday, January 7, 2009 at 10:48am.
Trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 100 mph and train B is traveling at 110 mph. Train A passes a station at 3:10 pm. If train B passes the same station at 3:40pm, at what time will train B catch train A?
4:30 pm
I am pretty sure that is incorrect. could someone please show me the correct expression to use to find the correct answer?

algebra  Damon, Wednesday, January 7, 2009 at 10:54am
call t time after a passes
distance a = 100 t
distance b = 110 (t.5)

0 = 100 t 110(t.5)
10 t = 55
5 = 5.5 hours
3:10 + 5:30 = 8:40 
algebra  drwls, Wednesday, January 7, 2009 at 10:57am
When train B passes the station, train A is (1/2 h)(100 mph) = 50 miles ahead. The distance between trains decreases at 10 miles per hour. Therefore B will catch A in five hours, at 8:10 pm

algebra  drwls, Wednesday, January 7, 2009 at 10:58am
Damon is correct; I should have added the 5 hours to 3:40, not 3:10