Question

The trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 100 mph and train Bis traveling at 120 mph. Train A passes a station at 11:20 pm. If train B passes the same station at 11:35 at what time will train B catch up to train A ?

Answer 1

let Sb = distance travelled by train B and Sa distance travelled by A - this is when they pass.
then Sb = Sa + 25 (25 miles - distance travelled by A in 15 minutes)
let t be the time
then Sb = 120t
and Sa = 100t
substituting:
120t = 25 + 100t
20t = 25
t = 1.25 hours
so the time when they pass is
11.35 + 1.15
= 12.50

Answer 2

Thanks !!!! :)

Answer 3

no probs