SOLUTION: Brenda and her husband Randy bicycled cross-country together. one morning,Brenda rode 30 miles. By traveling only 5 miles per hour and putting one more hour, Randy covered twice t
Question 344660: Brenda and her husband Randy bicycled cross-country together. one morning,Brenda rode 30 miles. By traveling only 5 miles per hour and putting one more hour, Randy covered twice the distance Brenda covered. what was the speed of each cyclist. show the solution. Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Brenda rode 30 miles.
By traveling only 5 miles per hour and putting one more hour, Randy covered
twice the distance Brenda covered.
what was the speed of each cyclist. show the solution.
:
From the above we can summarize:
B traveled 30 mi
R traveled 60 mi, but took 1 hr longer than B
:
Let s = B's speed
then
(s+5) = R's speed
:
Write a time equation; time = dist/speed
;
R's travel time - B's travel time = 1 hr - = 1
Multiply by s(s+5); results
60s - 30(s+5) = s(s+5)
:
60s - 30s - 150 = s^2 + 5s
30s - 150 = s^2 + 5s
Combine to form a quadratic equation
s^2 + 5s - 30s + 150 = 0
s^2 - 25s + 150 = 0
Factors to
(s-15)(s-10) = 0
Two equally valid solutions here
s = 15 mph
and
s = 10 mph
:
B's speed = 15; R's speed = 20
or
B's speed - 10; R/s speed = 15
;
:
Check using the 1st solution, find the times
R: 60/20 = 3 hrs
B: 30/15 = 2 hrs
----------------
differs: 1 hr
:
You can check using the 2nd solution, the same way
