SOCKS and SHOES
are in the dark, and on the floor there are six shoes of three colors,
and a heap of twenty-four socks, black and brown. How many socks and
shoes must you take into the light to be certain that you have a
matching pair of socks and a matching pair of shoes?
socks and four shoes would guarantee that you would have a matching
pair of each. Since there are only two colors of socks, it doesn't
matter how many are in the heap, as long as you take at least three, you
are certain to have two of the same. As for the shoes, you must pick
four, because selecting only three could result in one shoe in each of
the three colors!