PARAGRAPH "I"
Let and be the set of all relations from to that satisfy both the following properties:
- has exactly 6 elements.
- For each , we have .
Let and .
Let denote the number of elements in a set .
Passage
PARAGRAPH "I"
Let and be the set of all relations from to that satisfy both the following properties:
Let and .
Let denote the number of elements in a set .
If , then the value of is _____.
Official answer: 19.99
has ordered pairs. Remove those with :
That leaves pairs with . A relation in is any -element subset of these, so