As promised, here are the answers to the puzzles I gave on Monday.
1. Fumbling in the dark.
I would need to take 4 shoes to be sure of having a pair that match. If you took only 3 shoes, you could have taken one of each pair, so taking one more ensures you definitely have a pair of matching shoes.
Similarly, I would need to take 3 socks to be sure of having a pair that match.
2. Animal Farm
He would still have 50 horses - calling a cow a horse doesn't make it a horse.
3. Sum for simpletons
56 = 7 x 8
4. An up and down kind of existence
There is an absolute certainty that the monk will be at the same point on the road at the same time of day. Because the monk leaves later and arrives earlier on the second day than on the first day, there isn't a time of day on the second day that he was walking when he wouldn't have been on the first day. Therefore, if you imagine both journeys being made on the same day by two different monks, there comes a point where the two monks would have to walk past each other.