SOLUTION: Hi, I could really use some help with this problem: during the first part of the trip, a canoeist travels 47 miles at a certain speed. The canoeist travels 6 miles on the second

Algebra ->  Rational-functions -> SOLUTION: Hi, I could really use some help with this problem: during the first part of the trip, a canoeist travels 47 miles at a certain speed. The canoeist travels 6 miles on the second      Log On


   



Question 524608: Hi, I could really use some help with this problem: during the first part of the trip, a canoeist travels 47 miles at a certain speed. The canoeist travels 6 miles on the second part of the trip at a speed of 5 mph slower. The total time for the trip is 3 hours. What was the speed on each part of the trip?
Found 2 solutions by stanbon, richwmiller:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
during the first part of the trip, a canoeist travels 47 miles at a certain speed. The canoeist travels 6 miles on the second part of the trip at a speed of 5 mph slower. The total time for the trip is 3 hours. What was the speed on each part of the trip?
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1st Part DATA:
distance = 47 miles ; rate = r mph ; time = d/r = 47/r hrs.
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2nd Part DATA:
distance = 6 miles ; rate = r-5 mph ; time = d/r = 6/(r-5) hrs.
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Equation:
time + time = 3 hrs.
47/r + 6/(r-5) = 3
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47(r-5) + 6r = 3r(r-5)
47r - 235 + 6r = 3r^2-15r
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3r^2-68r+235 = 0
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Solve for the realistic value of "r":
r = 18.41 mph (rate on 1st part)
r-5 = 13.41 mph (rate on 2nd part)
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Cheers,
Stan H.
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Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
a+b=3
a*s=47
b*(s-5)=6
answers are not whole numbers.