If a boat can cover 250 km downstream and 150 km upstream in 5 hours each, then how much distance will a wooden object flowing in the river cover in 6 hours?

60 km

We know that,

Upstream Speed = Speed of Boat – Speed of current

Downstream Speed = Speed of Boat + Speed of current

Given,

A boat can cover 250 km downstream and 150 km upstream in 5 hours each.

Let the speed of the boat = x and the speed of the current = y

Then according to the question,

5(x + y) = 250      ....(A)

5(x - y) = 150      ....(B)

(A) - (B) we get,

5(x + y) - 5(x - y) = 250 - 150

= 10y = 100

= y = 10

Now, the distance covered by a wooden object flowing in the river in 6 hours =  6 × 10 = 60 km