Plutonians have three feet. Suppose the Plutonian Orfkleeg has a box with an infinite number each of red, blue, yellow, green, and white socks.
Plutonian etiquette requires that Orfkleeg wear three socks of the same color. It's dark, and Orfkleeg can't see.
What is the minimum number of socks Orfkleeg needs to take from the box to be ABSOLUTELY SURE there will be a suitable triplet of socks?
This is a Discrete Math question and it is in the section where the pigeonhole principle is introduced, so I am assuming that it needs to be used.