Question 504210: Please help me solve this problem:
London and Manchester are 200 miles apart.
Jack travels from London to Manchester at an average speed of 70mph.
Robert travels in the opposite direction, from Manchester to London, at an average speed of 30mph.
Knowing that they leave at the same time, in how much time will their paths cross each other?
Answer by oberobic(2304)   (Show Source):
You can put this solution on YOUR website! d = r*t is the basic distance equation
.
Jack's rate = 70 mph
Robert's rate = 30 mph
.
When Jack and Robert cross paths, they will have been traveling for the same amount of time. They will have traveled different distances, of course. But they will have been on the road and equal amount of time. In addition, when they cross paths, their combined distance traveled will = 200 miles.
.
30t + 70t = 200 miles
100t = 200
t = 2 hr
.
Always check the solution.
.
Jack will have traveled 2 hr *70 mph = 140 miles.
Robert will have traveled 2 hr * 30 mph = 60 miles.
OK.
.
Answer: They will cross paths in 2 hr.
.
Done.
|
|
|
