A man can swim in still water at 7.5 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 choices:  A) 1.7  B) 1.4  C) 1.1  D) 1.5  E) 2.5
M = 7.5   S = x   DS = 7.5 + x   US = 7.5 + x   7.5 + x = (7.5 - x)2   7.5 + x = 15 -2x   3x = 7.5   x = 2.5   Answer:2.5
<result>E</result>
A man can swim in still water at 7.5 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is?