SOLUTION: a man who can row 4 miles per hour in still water finds that it requires 6 1/2 hours to row upstream a distance requiring 3 1/4 hours to row downstream. what is the rate of the str

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: a man who can row 4 miles per hour in still water finds that it requires 6 1/2 hours to row upstream a distance requiring 3 1/4 hours to row downstream. what is the rate of the str      Log On


   

Question 775682: a man who can row 4 miles per hour in still water finds that it requires 6 1/2 hours to row upstream a distance requiring 3 1/4 hours to row downstream. what is the rate of the stream?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
ASSIGN VARIABLES
r = rate in still water, 4 mph
c = speed of the current, unknown
u = time traveled upstream, 6.5 hours
b = time traveled back downstream, 3.25 hours

Direction__________speed___________time___________distance
up_________________r-c_____________u______________d=(r-c)u
down_______________r+c_____________b______________d=(r+c)b

The essential equation is highlight%28%28r-c%29u=%28r%2Bc%29b%29 and the only unknown variable is c.
Solve for c.