A man can swim in still water at 4 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?  Choose the correct choice
A) 1.7
B) 1.9
C) 1.1
D) 1.5
E) 0.75
M = 4   S = x   DS = 4 + x   US = 4 + x   4 + x = (4 - x)2   4 + x = 8 -2x   3x = 4   x = 0.75   Answer:0.75
<result>E</result>
A man can swim in still water at 4 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?