Answers
Question: Number of sets from A, A X B, A X B X C
Correct Answer: 1, 2, 3.
Question: Counting elements (cartesian product)
Correct Answer: Elements from set 1 x elements from set 2 x ... elements from final set n
Question: Number of possible n-ary relations is
Correct Answer: 2**cartesian product.
Question: Special counts for Binary Relations
Correct Answer: Total binary relations: 2**n**2 - because size is shared between both sets
Question: Special counts for Binary Relations
Correct Answer: Reflexive relations: 2**(n**2 - n) where n is the element count, n**2 is the cartesian
product
Question: Special counts for Binary Relations
Correct Answer: Symmetric relations: 2**((n(n+1))/2)
Question: Special counts for Binary Relations
Correct Answer: Antisymmetric relations: 3**(n(n-1)/2) x 2**n
Question: How many tuples from A**n satisfy a condition
Correct Answer: n is tuple amount, k is the # you're looking for. binomial(n k) -- Combination(n k)
Question: Reflexive property on a n-ary relation
Correct Answer: ALL (a,a) of a relation
Question: Symmetric property on a n-ary relation
Correct Answer: if (a,b) and (b,a)
Question: Transitive property on a n-ary relation
Correct Answer: if (a,b) and (b,c) and (a,c) NOT (c,a)
Question: Antisymmetric property
Correct Answer: if no (a,b) (b,a) exist. MUST have atleast (a,b) OR (b,a)
Question: Equivalence relation
Correct Answer: reflexive, symmetric, transitive
Question: Partial order
Correct Answer: reflexive, antisymmetric, transitive
Question: What properties are in {(1,1),(2,2),(3,3)}?
Correct Answer: All four. Reflexive, Antisymmetric, symmetric, and transitive