A man can swim in still water at 9 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?	Options
A) 1.7  B) 1.4  C) 1.2  D) 1.5  E) 3
M = 9   S = x   DS = 9 + x   US = 9 + x   9 + x = (9 - x)2   9 + x = 18 -2x   3x = 9   x = 3   Answer: 3
<result>E</result>
A man can swim in still water at 9 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?