SOLUTION: In still water a boat averages 18 miles per hour. It takes the same amount of time to travel 33 miles downstream, with the current, as 21 miles upstream, against the current. Wha

Algebra ->  Rational-functions -> SOLUTION: In still water a boat averages 18 miles per hour. It takes the same amount of time to travel 33 miles downstream, with the current, as 21 miles upstream, against the current. Wha      Log On


   

Question 362901: In still water a boat averages 18 miles per hour. It takes the same amount of time to travel 33 miles downstream, with the current, as 21 miles upstream, against the current. What is the rate of the water's current?
Answer by HasanSahin(52) About Me  (Show Source):
You can put this solution on YOUR website!
There is no importance of the average speed of boat as it's useless variable to calculate the current speed of water..If the boat can go 33 and 21 miles in same amount of time we could think such that;
Assume "x" as boat speed without effect of current and "y" as the current speed..
x + y = 33
x - y = 21
Sum up the equations therefore >> 2x = 54 and x = 27 >>
Put "x" into any equation you'll get >> y = 6 miles/h
RF.