A man can row 9 kmph in still water. When the river is running at 3.1 kmph, it takes him 1 hour to row to a place and black. What is the total distance traveled by the man?  Choose the correct choice from the following options:
A) 2.21
B) 2.48
C) 9.24
D) 7.29
E) 7.94
M = 9   S = 3.1   DS = 12.1   US = 5.9   x/12.1 + x/5.9 = 1   x = 3.97   D = 3.97 * 2= 
<gadget id="calculator">3.97 * 2</gadget>
<output>7.94</output>
7.94   Answer: 7.94
<result>E</result>
A man can row 9 kmph in still water. When the river is running at 3.1 kmph, it takes him 1 hour to row to a place and black. What is the total distance traveled by the man?