The speed at which a man can row a boat in still water is 9.5 kmph. If he rows downstream, where the speed of current is 8.5 kmph, what time will he take to cover 45.5 metres?  Pick:
A) 18 seconds  B) 8.4 seconds  C) 5 seconds  D) 9.1 seconds  E) 9.5 econds

Rationale: "speed of the boat downstream = 9.5 + 8.5 = 18 kmph = 18 * 5 / 18 = 5 m / s hence time taken to cover 45.5 m = 45.5 / 5 = 9.1 seconds . answer : d"
Answer: D