The speed at which a man can row a boat in still water is 6 km/hr. If he rows downstream, where the speed of current is 3 km/hr, how many seconds will he take to cover 110 meters?
Choose the correct choice from the following answers.
A) 40 B) 44 C) 48 D) 52 E) 56

Rationale: "the speed of the boat downstream = 6 + 3 = 9 km / hr 9 km / hr * 5 / 18 = 2.5 m / s the time taken to cover 110 meters = 110 / 2.5 = 44 seconds . the answer is b ."
Answer: B