There is a little cute bird which took 2 hours flying from A to B. it rained before she came back. Therefore, it took her 4 hours flying back from B to A. why? (the same route exactly, no stop on the way)
I believe I heard this one a long time ago, so I won't (yet) share the solution I remember - except that I'm not sure "no stop along the way" is correct. Perhaps "no landings along the way" would be better? Or perhaps there's another solution I can't think of.
Are you sure the bird could get enough lift off with just the one wing flapping? I mean if an airplane loses a wing it crashes. I think the bird just decided to take the train and that's why it took so long. Mark