Here's a new puzzle. It's not easy. And it lures people into an incorrect answer. We'll see if Dr. Kim has ever used this one for his class.
For a round-trip flight between New York and Los Angeles and back to New York, how will a constant and uniform wind affect the total elapsed time of the flights compared to having no wind? Will a constant wind, uniform across both legs of the trip, make the total flight time longer, make it shorter, or have no effect?