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?
Answer & explanation
Correct answer: option 4
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