A person can row at 9 kmph and still water. He takes 7 1/2 hours to row from A to B and back. What is the distance between A and B if the speed of the stream is 1 kmph? Answers.
A) 33  B) 28  C) 29  D) 54  E) 20
Let the distance between A and B be x km.   Total time = x/(9 + 1) + x/(9 - 1) = 7.5   =&gt; x/10 + x/8 = 15/2 =&gt; (4x + 5x)/40 = 15/2 =&gt; x   = 33 km.   33nswer:33
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A person can row at 9 kmph and still water. He takes 7 1/2 hours to row from A to B and back. What is the distance between A and B if the speed of the stream is 1 kmph?