SOLUTION: A boat can travel 26 mph in still water. If the boat can travel 100 miles with the current in the same time it can travel 80 miles against the current, find the rate of the current

Algebra ->  Equations -> SOLUTION: A boat can travel 26 mph in still water. If the boat can travel 100 miles with the current in the same time it can travel 80 miles against the current, find the rate of the current      Log On


   

Question 1095989: A boat can travel 26 mph in still water. If the boat can travel 100 miles with the current in the same time it can travel 80 miles against the current, find the rate of the current r in miles per hour. (Enter an exact number as an integer, fraction, or decimal.)
Found 3 solutions by jorel1380, MathTherapy, ikleyn:
Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
Let r be the speed of the current. Then:
100/26+r=80/26-r
2080+80r=2600-100r
180r=520
r=2.89 mph
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Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

A boat can travel 26 mph in still water. If the boat can travel 100 miles with the current in the same time it can travel 80 miles against the current, find the rate of the current r in miles per hour. (Enter an exact number as an integer, fraction, or decimal.) 
Correct answer: highlight_green%2826%2F9%29

Answer by ikleyn(52850) About Me  (Show Source):
You can put this solution on YOUR website!
.
100%2F%2826%2Br%29 = 80%2F%2826-r%29 ====>


5*(26-r) = 4*(26+r)  ====>


130 - 5r = 104 + 4r  ====>  130-104 = 4r + 5r  ====>  9r = 26  ====>  r = 26%2F9 miles per hour is the current rate.