Bunuel wrote:
Shelly rows 4m kilometers downstream at 6x kilometers per hour. Then she turns around and rows m/6 kilometers upstream at 2x kilometers per hour. What is Shelly's average rowing speed in kilometers per hour during the entire journey?
A. 50x/9
B. 50x/(9m)
C. 50/9
D. 50m/9
E. 50mx/9
The average speed will certainly be independent of "m" and certainly be dependent on "x". Only A satisfies these conditions. So answer is A without even solving the question.
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