RRB NTPC · Question 110
Speed of a boat in still water is 12 kmph and that of the current is 3 kmph. A man rows a boat upstream up to 135 km and returns downstream to the starting point. Find the total time taken for the entire journey in hours.
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Answer: (A) 24
Explanation
Upstream speed = 12 − 3 = 9 km/h and downstream = 15 km/h. Time = 135/9 + 135/15 = 15 + 9 = 24 hours.