Question 1105628
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The entire round trip lasted 3 hours + 6 hours = 9 hours, as described in the condition.


At no wind, the round trip will take 6 + 6 = 12 hours, <U>PROBABLY</U>.



If you (or somebody else) will disprove this solution, I will say that in a way it is formulated, it is NOT a Math problem at all.