In how many hours will they be 315 miles apart?

Question

Two trains start from the same station at the same time and travel in opposite directions. One train
travels at an average rate of 40 mph, the other at 65 mph.  

Answer 1

The separation rate of the two trains is 40 mph + 65 mph = 105 mph

 

distance = rate*time

315 mi = 105 mph * time

315/105 = time

3 hours = time