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?

BRAlNBOLT May 28, 2024

#1**+1 **

After Dirk finally finishes the race, Edith has ran 14 km while Foley has ran 9 km.

This essentially means that Foley is 9/14 as fast as Edith.

This means when Edith has ran 24 km, Foley has ran \(24 (9/14) ≈ 15.43 \) km.

So Foley is \(24 - 15.43 ≈ 8.57\)km behind Edith!

Thanks! :)

NotThatSmart May 28, 2024

#1**+1 **

Best Answer

After Dirk finally finishes the race, Edith has ran 14 km while Foley has ran 9 km.

This essentially means that Foley is 9/14 as fast as Edith.

This means when Edith has ran 24 km, Foley has ran \(24 (9/14) ≈ 15.43 \) km.

So Foley is \(24 - 15.43 ≈ 8.57\)km behind Edith!

Thanks! :)

NotThatSmart May 28, 2024