You are racing a child that you are twice as fast as and you want to give him a head start in a race from one side of a field to the other. How much of a head start should you allow so that you will come close to finishing the race even? Draw a picture and label the length of the field as L and the head start distance as H. What is the length that the child needs to run? If your speed is S what is the child's speed? You want to finish at nearly equal times; the time that it takes you would be L/S (the distancerun divided by the speed run), what would it be for the child? Set those equal and solve for H.