SOLUTION: Two friends Mark and John went jogging. Their relative rates are as follows: Mark jogs a 2.6 km stretch for 1 hr while it takes John to jog the same stretch for 45 min. Mark starte

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Two friends Mark and John went jogging. Their relative rates are as follows: Mark jogs a 2.6 km stretch for 1 hr while it takes John to jog the same stretch for 45 min. Mark starte      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 486783: Two friends Mark and John went jogging. Their relative rates are as follows: Mark jogs a 2.6 km stretch for 1 hr while it takes John to jog the same stretch for 45 min. Mark started jogging alone for 2 hrs. At this instant John starting from the same point as Mark began to jog. In how many hours will John overtake Mark if ever he will?
Answer by chessace(471) About Me  (Show Source):
You can put this solution on YOUR website!
Rate M = 2.6 km/hr
Rate J = 2.6 / .75 = 3.467
As usual, x = answer = hours needed by J to catch M.
The distance at that point will be same for both:
3.467 x = 2.6 * (x + 2)
(3.467 - 2.6) x = 2 * 2.6
Note that this is also the expression for observed (by either jogger) relative speed * time = distance between them.
0.867 x = 5.2
x = 6 hours.