Jul 7, 2015
40
1
Status
Pre-Dental
Jack and Jill ran a race to the well. Jill runs at 5 miles an hour, and Jack runs
at 6 miles an hour. After Jack finished the race, he had to wait 15 minutes before
Jill finished. How long was the race?

could someone simplified the problem and provide easier explanation on this one?
 
Jan 9, 2015
126
35
displacement = velocity*time

Let x be the time of the race
After x hours, Jack distance is 6x and Jill distance is 5x.
Since Jack had to wait 15 minutes or 0.25 hours for Jill to finish, Jill has to run extra 0.25*5 miles to meet Jack.
Thus 5x + 0.25*5 = 6x (This equation just tells you that Jill has to run the same distance as Jack)
Solving for x = 1.25 hours

The race was 1.25 hrs long for Jack and 1.5 hrs long for Jill.
 
Last edited: