A man can row a boat at 15 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 60 km downstream?
Answers:
A) 30/16 hours B) 80/13 hours C) 30/73 hours D) 30/13 hours E) 20/7 hours
Speed downstream = 15 + 6= 
<gadget id="calculator">15 + 6</gadget>
<output>21</output>
21 kmph.   Time required to cover 60 km downstream= d/s = 60/21   = 20/7 hours.   Answer:20/7 hours
<result>E</result>
A man can row a boat at 15 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 60 km downstream?