Question 592773: At the beginning of a walk, roberto and juanita are 9.9 miles apart. If they leave at the same time and walk in the same direction, Roberto overtakes Juanita in 11 hours. If they walk towards eachother, they met in 1 hour.What are their speeds?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! At the beginning of a walk, Roberto and Juanita are 9.9 miles apart.
If they leave at the same time and walk in the same direction, Roberto overtakes Juanita in 11 hours.
If they walk towards each other, they met in 1 hour.
What are their speeds?
:
Let r = R's walking speed
Let j = J's walking speed
then
(r+j) = effective speed when walking towards each other
(r-j) = effective speed when walking the same direction
:
Write a distance equation for each scenario
:
11(r-j) = 9.9
1(r+j) = 9.9
Divide both sides of the 1st equation by 11, add to the 2nd equation
r - j = 9.9/11
r - j = 0.9
r + j = 9.9
--------------adding eliminates j, find r
2r = 10.8
r = 10.8/2
r = 5.4 mph is R's speed
:
Use the 2nd equation to find j
5.4 + j = 9.9
j = 9.9 - 5.4
j = 4.5 mph is J's speed
:
:
Check these solutions in the 1st equation
11(5.4-4.5) =
11(.9) = 9.9; confirms our solutions of r=5.4; j=4.5
|
|
|
