Two sets
Source: 2010 AIMEII #8
April 1, 2010
AIME
Problem Statement
Let be the number of ordered pairs of nonempty sets and that have the following properties:
• \mathcal{A} \cup \mathcal{B} \equal{} \{1,2,3,4,5,6,7,8,9,10,11,12\},
• \mathcal{A} \cap \mathcal{B} \equal{} \emptyset,
• The number of elements of is not an element of ,
• The number of elements of is not an element of .
Find .