A person can row at 9 kmph and still water. He takes 5 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?
Choose the most appropriate option:
A) 32 B) 28 C) 29 D) 24 E) 20
Let the distance between A and B be x km.   Total time = x/(9 + 1) + x/(9 - 1) = 5.5   =&gt; x/10 + x/8 = 11/2 =&gt; (4x + 5x)/40 = 11/2 =&gt; x   = 24 km.   Answer:24
<result>D</result>
A person can row at 9 kmph and still water. He takes 5 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?