+413 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 $15$ km behind. When Edith finishes the race, how far behind is Foley, in km?
+1946 So, first let's analyze the question.
Note that when Dirk finishes, Edith has ran 14km and Foley has run 9km.
Well, this means Foley runs 9/14 as fast as Edith.
So when Edith runs the entire 24km, Foley has ran 24(9/14)≈15.43km
Which means that Foley is 24−15.43≈8.57km behind Edith.
So 8.57 km is our answer!
Thanks! :)
