A man can swim in still water at 12 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is? Choose the correct choice from the following answers:	A) 1.7	B) 2.67	C) 1.2	D) 1.5	E) 4
M = 12   S = x   DS = 12 + x   US = 12 + x   12 + x = (12 - x)2   12 + x = 24 -2x   3x = 12   x = 4   Answer: 4
<result>E</result>
A man can swim in still water at 12 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?