distance

[demoskopico]

Two trains continuously travel between Washington DC and Baltimore, which is 120 miles away. They start simultaneously, train A at Washington and train B at Baltimore, and run at 30 and 90 mph respectively. The station turnaround times are negligible. What is the distance between the point where the trains meet for the first time and the point where they meet for the second time?

0
30 miles
60 miles
90 miles
120 miles

[kevin]

Can you see that train A takes 4 hours to complete one leg of the return trip, whereas B takes only 120/90 = 4/3 of an hour

Thus they will first meet when they have travelled a total of 120 miles.

They will next meet when the faster train has travelled 120 miles more than the slower one.

Can you work out the details?