A man can row a boat at 21 kmph in still water. If the speed of the stream is 7 kmph, what is the time taken to row a distance of 70 km downstream? Answers: A) 11/9 B) 5/7 C) 3/2 D) 5/3 E) 5/2
Speed downstream = 21 + 7= 
<gadget id="calculator">21 + 7</gadget>
<output>28</output>
28 kmph.   Time required to cover 60 km downstream= d/s = 70/28   = 5/2 hours.   Answer: 5/2
<result>E</result>
A man can row a boat at 21 kmph in still water. If the speed of the stream is 7 kmph, what is the time taken to row a distance of 70 km downstream?