How much is one and one half dozen?

Answer 1

"18"

To be contrary I would say that the answer is bit more complex than that.

The question is ambiguous as a "math, algebra, arithmetic" question; answers could be:

• 18 ("and" is being used as a substitution for "plus" with an assumption that "one" is really "one dozen")
• 7 ("and" is being used as a substitution for "plus" with no assumption that "one" is really "one dozen")
• False ("and" is being used as a boolean operator)

As an English usage question the answer is indeed generally agreed upon as being 18.