SOLUTION: ronald can row 24 miles in 3 hours when he rows with the current. against the same current, ronald can now only 2/3 of this distance in 4 hours. find the rate of the current (use 2

Let u be the rate of rowing in still water and v be the rate of the current.


Then the effective rate downstream is

    u + v =  = 8  miles per hour.     (1)


while the effective rate upstream is

    u - v =  = 4  miles per hours.    (2)   (Notice 16 is 2/3 of 24 miles)


Now subtract equation (2) from equation (1).


You will get

    2v = 8 - 4 = 4

     v         = 4/2 = 2 miles per hour.


ANSWER.  The rate of the current is  2 miles per hour.