A train leaves Boston at 4:00 PM. A second train leaves the same city in the same direction at 8:00 PM. The second train travels

84mph faster than the first. If the second train overtakes the first at 10:00 PM, what is the speed of each of the two trains?

42 mph 126 mph

Step-by-step explanation:

It takes 2 hours for the second train to catch the first, so the first must have had a head start of (2 h) (84 mi/h) = 168 miles.

The first train achieved that head start in 4 hours, so its speed was ...

(168 mi) / (4 h) = 42 mi/h

The second train was 84 mi/h faster so its speed was ...

42 mi/h + 84 mi/h = 126 mi/h

___

The two trains met at a distance of 252 miles from Boston.