A boat takes 8 hrs to cover a distance while travelling upstream whereas while travelling downstream, it takes 6 hrs. if the speed of the current is 4 Km/hr, what is the speed of the boat in still water in Km/hr?

28

Speed of current i.e. y = 4km/hr

Speed of boat in still water i.e. x = ?

Downstream speed = x + y

Upstream speed = x - y

Speed = \(\frac{ Distance}{ Time}\)

Distance = Speed x Time

According to the question:

Distance = Downstream speed x 6

Distance = (x + y) 6 ------------(1)

Distance = Upstream speed x 8

Distance = (x - y) 8 -------------(2)

From 1 and 2 equation, we can deduce:

6 (x + y) = 8 (x - y)

6( x + 4) = 8 ( x - 4)

6x + 24 = 8x - 32

2x = 56

x = 28 km/hr