math/story problem
posted by Please .
Trains a and b are traveling in the same direction on parallel tracks;Train a is traveling 40mph and train b is traveling 50mph. Train A passes a station at 8:15 am. If train b passes the same station at 8:27 am what time will train b catch up to train a?
I know this is a distant rate a time question but cannot seem to write out the correct formula and arrive at a correct answer.

The distance between the trains decreases at a rate of 50  40 = 10 mph = 1/6 mile per minute.
At 8:27 PM, train A is (1/6 h) * 40 miles/h = 40/6 miles ahead of B.
The 40/6 mile gap between trains will become zero after
t = (40/6 mile)/(1/6 mile/minute)
= 40 minutes 
so they will meet up at 9:07 am?

Yes