Train 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 pases a station at 4:10 a.m. If train B passes the same station at 4:22 a.m., at what time will train B catch up to train A?

1 answer

4:22 - 4:10 = :12 min = 0.2 h = make-up time for train B.

Train A time = t hrs,
Train B time = (t - 0.2) hrs.

d(A) = d(B) = Distance traveled.

100t = 110(t - 0.2),
100t = 110t - 22,
100t - 110t = -22,
-10t = -22,
t = 2.2 hrs,

(t - 0.2) = 2.2 - 0.2 = 2.0 hrs =
time to catchup.