A BOATMAN ROWS TO A PLACE 48KM DISTANT AND BACK IN 14 HOURS; HE FINDS HE CAN ROW 4KM WITH THE STREAM IN THE SAME TIME AS 3KM AGAINST THE STREAM. FIND THE RATE OF THE STREAM?

Answer 1

If his rowing speed is r, and the current speed is c, then

(r+c)/4 = (r-c)/3
48/(r+c) + 48/(r-c) = 14

c = 1

Answer 2

Suppose he move 4 km downstream in x hours. Then,

Speed downstream = 4 km/hr.
x
Speed upstream = 3 km/hr.
x
48 + 48 = 14 or x = 1 .
(4/x) (3/x) 2
So, Speed downstream = 8 km/hr, Speed upstream = 6 km/hr.

Rate of the stream = 1 (8 - 6) km/hr = 1 km/hr.
2