Danielle and David will run in a marathon. Danielle's running pace is 7 miles per hour, and David's is 4 miles per hour. If they both start at the same point, how many minutes should it take Danielle to be mile ahead of David?

I believe it is 20 minutes.

Step-by-step explanation:

It takes 1 hour for Danielle to run 3 miles ahead of David.  You would have to divide 3 hours by 3 which is 1 mile. You have to do the same for the time it took to run 3 miles ahead (1 hour).  1 hour = 60 minutes and 60 divided by 3 is 20. This means it should take Danielle 20 minutes to be 1 mile ahead of David.

Hope this explanation helps!

10 minutes

Step-by-step explanation:

I've had the same question, and although the other answer was correct, the question asked how long it would take to be 1/2 mile ahead, so I guess you'd do 20 divided by 2 in order to get the correct answer. Hopefully this helps you, if not, ignore me :)