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?	Choices.
A) 60 km	B) 87 km	C) 89 km	D) 67 km	E) 24 km
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 km
<result>E</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?