A train going 60 mph left several minutes before the 63mph train. Traveling on parallel tracks the faster train reaches the slower one in 3 hours. How many minutes head start did the slower train have?

Answer 1

Both trains had traveled the same distance:

d1 = d2.

60t = 63*3 = 189 mi.
t = 3.15h.

3.15h - 3h = 0.15h = 9min head start.