__Question #1:__ What's non-orientable and lives at the bottom of the ocean?
__Answer #1:__ Mobius Dick

When Nakaso didn't understand the humor, Andy Chermak, mathematician at Kansasa State University, explained: "A Mobius strip is a surface with only one side, formed by giving a half-twist to a narrow, rectangular strip of paper and then pasting the two ends together. The strip is 'non-orientable' because there is no true north or south."

__Question #2:__ What's yellow and implies the axiom of choice?

__Answer #2:__ Zorn's Lemma

When Nakaso didn't understand the humor, Nora Hartsfield, mathematician at Western Washington University, explained: "Zorn's Lemmais a mathematical device in which each linearly ordered subset of a partially ordered set, contains a maximal element. It's also nice to know what an axiom of choice is."

Nakaso remained puzzled. So, Chernak noted that after a mathematical explanation, math jokes aren't "all that funny."
Mary Kellogg, Manhatten Community College (NY), added that there are some funny mathematical jokes, but "They're very much inside jokes. The things that mathematicians laugh at generally would not be funny to anyone else."

Source: *D. Nakaso's "They Talk in Numbers and Joke in Tongues," **Los Angeles Times*, January 1985