Question 1076402
Let t be the time it takes, in hours, for the trains to meet. The freight train has a two hour head start, at 50 mph. So:
70t+50t+100=280
120t=180
t=180/120 or 3/2 hours after the express train left Memphis before the two trains meet. &#9786;&#9786;&#9786;&#9786;