In a fixed time a boy swims double the distance along the current that he swim against the current I......

In a fixed time, a boy swims double the distance along the current that he swim against the current. If the speed of the speed current is 3 km/ hr, the speed of the boys in still water is :

Let the speed of boy in still water = x km/h.
Let the speed of current, y = 3 km/h
Downstream speed = (x + 3) km/h
Upstream speed = (x - 3) km/h
According to the question,
Let the time = t hours.
(x + 3) × t = 2 (x + 3) × t
(x + 3) × t = 2 (x - 3) × t
x + 3 = 2x – 6
 x = 9km/h

By: Manpreet kaur