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Three runners, Dirk, Edith, and Foley all start at the same time for a 24 km race,
and each of them runs at a constant speed.
When Dirk finishes the race, Edith is 10 km behind, and Foley is 8 km behind .
When Edith finishes the race, how far behind is Foley, in km?
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From the problem, when Dirk completed the race, Edith ran 24-10 = 14 kilometers;
Foley ran 14- 8 = 6 kilometers.
From it, we conclude that Edith rate to Foley rate ratio is 14/6.
So, when Edith will complete 24 kilometers, the ratio of distances Edith and Foley run
will be the same 14/6. It gives the proportion
24 14
---------- = ----.
Foley ran 6
From this proportion
Foley run (when Edith finished) = = = = 10.28571 kilometers.
Hence, when Edith finishes the rate, Foley is 24-10.2857 = 13.7143 kilometers behind (rounded value).
Solved.