Train A and B are traveling in the same direction .......?

Question

Train A and B are traveling in the same direction on parallel tracks. Train A is traveling at 40 miles per hour and train B is traveling at 60 miles per hour. Train A passes a station at 3:25pm. If train B passes the same station at 3:40pm., at what time will train B catch up to train A?

Answer 1

rate                           time                     distance

train a     40 m/h                          t+ 15min

train b      60m/h                           t

      

     40(t +15) = 60t

       40t + 600 = 60 t

              600= 60t-40t

               600 =20t

                  30 = t

they will arrive at their destination in 30 min

train b will pass train at3: 55