Question 1135240
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The solution from tutor @ikleyn uses probably the most common algebraic approach to the problem.<br>
Here is a different method that I like to use on problems like this.<br>
(1) The first train traveled from 1pm until 10pm, 9 hours; the second traveled from 4pm until 10pm, 6 hours.<br>
(2) The distances are the same, and the ratio of the times is 3:2.  That means the ratio of speeds is 2:3.<br>
(3) If the ratio of the speeds is 2:3 and the difference in the speeds is 30mph, then the two speeds are 60mph and 90mph.