.
The condition says
- = 2 (it is 2 hour difference, and each the ratio is the time for corresponding plane)
where d is the unknown distance.
To solve it, multiply the equation by 300*510 (both sides). You will get
510d - 300 = 2*300*510, or
210d = 2*300*510 ====> d = = = 1457.1 miles.
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In such problems, getting an integer solution/answer is considered as a reward to a student for his efforts (joke).
In opposite, absence of the integer solution is an evidence that the problem is badly designed (it is my personal opinion, which is not a joke in this case).
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For introductory lessons on Travel and Distance problem see the lessons
- Travel and Distance problems
- Travel and Distance problems for two bodies moving in opposite directions
- Travel and Distance problems for two bodies moving in the same direction (catching up)
in this site.