Two trains started from the same point. At 8:00 am the first train traveled East at the rate of 80 mph. At 9:00 am, the second train traveled West at the rate of 100 mph. At what time were they 530 miles apart? Choose the correct answer
A) 11:30 am B) 10:30 am C) 8:30 am D) 7:30 am E) 9:30 am
When the first train has traveled for t hours the second train will have traveled (t - 1) hours since it started 1 hour late. Hence if D1 and D2 are the distances traveled by the two trains, then   D1 = 80 t and D2 = 100 (t - 1)   Since the trains are traveling in opposite direction, the total distance D between the two trains is given by   D = D1 + D2 = 180 t - 100   For D to be 530 miles, we need to have   180 t - 100 = 530   Solve for t   t = 3 hours 30 minutes.   8 am + 3:30 = 11:30 am   11:30 amnswer 11:30 am
<result>A</result>
Two trains started from the same point. At 8:00 am the first train traveled East at the rate of 80 mph. At 9:00 am, the second train traveled West at the rate of 100 mph. At what time were they 530 miles apart?