|
Question 104908: mary and sue are 30 miles apart. if they leave at the same time andride in the same direction, mary overtakes sue in 6 hours. if they ride towards each other they pass each other in 1 hour. what are their speeds?
Answer by HyperBrain(694)   (Show Source):
You can put this solution on YOUR website! I'm not a great tutor here. Ican't show you any drawing. So, draw as I say:
Draw that Mary and Sue are apart. Mark that their 30 miles away form each other.(no need to be scaled).
If you overtake, this means that you reach the same point where the other object/person is.
Let x= speed of Mary
____y= speed of Sue
Come to think of this fact: it is MARY who overtook. This means that Mary MUSt be FASTER than Sue!
After 6 hrs, they're at the same point. And take note: Sue is already ahead by 30 miles when they started. So,
_______________________
_______________________
________________________
Now let's INVESTIGATE the second case: Mary and Sue heading toward each other.
They met in i hr. At that instant, the sum of the distance they had traveled is 30 miles.
So,
______________________
But,
________________________
Thus,
_______________________
__________________________
____________________________
_____________________________
Again,
________________________
Then,
________________________
________________________
Therefore, Mary travels at a speed of 17.5 mph while Sue travels at the speed of
12.5 mph!
Power up,
HyperBrain!
|
|
|
| |
