SOLUTION: A crew of four practices rowing up a river, then back down for the same distance. The current of the river is 3 km/hr. Currently the crew can can row at 15 km/hr in still water and

Question 683004: A crew of four practices rowing up a river, then back down for the same distance. The current of the river is 3 km/hr. Currently the crew can can row at 15 km/hr in still water and makes the round trip in 25 minutes. How far upstream did they row?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
Let distance be x
upstream speed = 15-3=12 mi/h
downstream speed = 15+3=18 mi/h
Time upstream + time downstream = 25 minutes= 25/60 = 5/12 hours
t=d/r
x/12 + x/18 = 5/12
LCD = 36
multiply equation by 36
3x+2x=15
5x=15
x=3 miles

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