Divide the set on integers into subsets such that any of two members, a and b, of a subset are co...
Let A={1,2,3,4}. Pick a subset B⊆A uniformly among the 2^4 subsets (i.e. the power set ofA) and let X be its size. Then likewise pick a subset C⊆B uniformly from the power set of B and let Y be its size. Give the joint p.m.f of (X, Y) and compute E(X−Y). Hint: X, Y can take value 0 if you pick the empty set. You can either write down a table or a compact expression of the form P(X=i, Y=j).
Let P(X) be the power set of a non-empty set X. For any two subsets A and B of X, define the relation A B on P(X) to mean that A union B = 0 (the empty set). Justify your answer to each of the following? Isreflexive? Explain. Issymmetric? Explain. Istransitive? Explain.
Exercise 1.10. Prove for any set X and for any subsets A and B of X, the set A can be written as a disjoint union in the form A = (A ∩ B) ∪ ̇ (A ∩ Bc).
Exercise 1.10. Prove for any set X and for any subsets A and B of X, the set A can be written as a disjoint union in the form
4. Ranking/Unranking Subsets. Let A be a set of n elements and set Sk(A) be the collection of all k-element subsets of A. Recall that |Sk(A)I - (a.) (8 points) Describe a ranking algorithm to rank a k-element subset of an n-element set. (b.) (8 points) Describe an unranking algorithm to unrank an integer 0 < s< [into a ithm to unrank an integer 0 S s <C) k-element subset of an n-element set. (c.) (10 points) As examples, let...
4) Let D be the set of all finite subsets of positive integers. Define a function (:2 - D as follows: For each positive integer n, f(n) =the set of positive divisors of n. Find the following f (1), f(17) and f(18). Is f one-to-one? Prove or give a counterexample.
2. Given the set S-ta,b,c,d,e,f,g,h) a) How many subsets does S have? b) How many subsets have exactly 5 elements? c) A subset is randomly chosen for the collection of all possible a) b) c) subsets. What is the probability that it contains exactly 3 elements? d) A subset is chosen at random from all the subsets. d) What is the probability that it contains the element a?
1. A universal set, with n(U)70, is partitioned into three subsets: A, B, and C. If n(B) 3-n(A), and n(C) 2-n(B), find the number of elements in the subset A. 2. A license plate consists of eight symbols on each plate, where the first three symbols are letters of the alphabet and the following five symbols are the digits selected from the set f0, 1, 2, 3, 4, 5, 6, 7, 8, 9)? How many license plates can be produced...
Let X be a set and let T be the family of subsets U of X such
that X\U (the complement of U) is at most countable, together with
the empty set. a) Prove that T is a topology for X. b) Describe the
convergent sequences in X with respect to this topology. Prove that
if X is uncountable, then there is a subset S of X whose closure
contains points that are not limits of the sequences in S....
P.4 Prove that for any set of integers {ao, aj, a2,..., ax), the integer n=ax. 10% +ax-1·10k-1 + ... + 01.10+ 0 is congruent to E-01–1)' a; (mod 11). What significance does this hold when the ai are restricted to the set {0,1,2,3,4,5,6,7,8,9}?