A man whose speed is 7.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey?
Pick:
A) 10
B) 8
C) 9
D) 7.2
E) 6
M = 7.5   S = 1.5   7.2S = 9   US = 6   AS = (2 * 9 * 6) /15= 
<gadget id="calculator">(2 * 9 * 6) /15</gadget>
<output>36/5 = around 7.2</output>
7.2   Answer: 7.2
<result>D</result>
A man whose speed is 7.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey?