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?	Choose the correct choice from the following answers:  A) 50x/9  B) 50x/(9m)  C) 50/9  D) 50m/9  E) 50mx/9
Total distance covered = 4m + m/6 = 25m/6   Total time taken = 4m/6000x + (m/6)/2000x = 9m/12000x = 3m/4000x   50x/9verage speed = Total distance/Total Time taken = (25m/6)/(3m/4000x)   = 50,000x/9 mt/hr   = 50x/9 km/hr   Option 50x/9.
<result>A</result>
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?