Question 797197: hello sir / ma'am, im having trouble with this:
a boat can travel 8 miles per hour in still water. the boat travels upstream for a certain time in a river whose current flows 2 miles per hour. then, the boat returns to its starting point. if the trip, up and back consumed 8 hours, how long did the boat travel upstream?
thank you so much!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! a boat can travel 8 miles per hour in still water. the boat travels upstream for a certain time in a river whose current flows 2 miles per hour. then, the boat returns to its starting point. if the trip, up and back consumed 8 hours, how long did the boat travel upstream?
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Upstream DATA:
time = t hrs ; rate = 8-2 = 6 mph ; distance = r*t = 6t miles
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Downstream DATA:
time = 8-t hrs ; rate = 6+2 = 8 mph ; distance = r*t = 8(8-t) miles
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Equation:
distance up = distance down
6t = 8(8-t)
6t = 64-8t
14t = 64
t = 4.5714 hours (time to travel upstream)
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Cheers,
Stan H.
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