A boat running upstream covers a distance of 10 km in 30 min and while running downstream, it covers the same distance in 25 min away and return, then the speed of the water current is?
Correct Answer: 1/2 km/h
Explanation:
Speed upstream = 10 / (30/60) = (10 x 60)/30 = 20 km/h
Speed downstream = 10/(25/60) = (10 x 60)/25 = 24 km/h
∴ Speed of the river's current = (24 - 20)/2 = 4/2 = 2 km/h
