SOLUTION: A motorboat can maintain a constant speed of 18 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 44 minutes; the return trip takes 28 minu

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Question 1160536: A motorboat can maintain a constant speed of 18 miles per hour relative to the water. The boat makes a trip upstream to a certain point in 44 minutes; the return trip takes 28 minutes. What is the speed of the current?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
current speed=c
upstream speed is 18-c mph
and in 44 minutes, the boat goes (44/60)(18-c) miles
downstream it goes 18+c mph and in 28 minutes goes (28/60)(18+c) miles
Those are equal
the 60s cancel out
so 44(18-c)=28(18+c)
792-44c=504+28c
288=72c
c=4 mph
upstream 14 mph net and goes 14*44/60 miles or 10.267 miles
downstream 22 mph and goes 22*28/60 miles or 10.267 miles