SOLUTION: on a weekend outing, bernard rents a motorboat for 10 hours to travel down the river and back. The rental operator tells him to go for 4 hours downstream, leaving 6 hours to return

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: on a weekend outing, bernard rents a motorboat for 10 hours to travel down the river and back. The rental operator tells him to go for 4 hours downstream, leaving 6 hours to return      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 146133: on a weekend outing, bernard rents a motorboat for 10 hours to travel down the river and back. The rental operator tells him to go for 4 hours downstream, leaving 6 hours to return upstream.
If the river current flows at a speed of 4mph how fast must Bernard teavel in order to return in 10 hours?
How far downstream did Bernard go before he turned back?

Answer by dealkit(1) About Me  (Show Source):
You can put this solution on YOUR website!
Assume the boat speed is Xmph
the river speed is 4mph
Since the operators asked him to turn back after 4 hours
and return journey will take 6 hours
(remember that the speed is added in one way, and reduced in return)
(x+4) * 4 = (x-4) * 6
4x+16 = 6x-24
2x = 40
x = 20
speed of boat must be 20mph