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# Combinatorics

### Counting and Combinations

Problem 1) How many bits does 10^100 (ten power one hundred) have if written in base 2? problem 2) Find the number of all 20-digit integers in which NO two consecutive digits are the same Please explain to me the steps, don't just give me the answer, thank you very much.

### Combinations of Letters and Digits

Could someone show me how to solve the following. 20. How many different license plates can be made if each license plate consists of three letters followed by three digits or four letters followed by two digits?

### Set Partitions and Bit Strings

Which of these collections of subsets are partitions on the set of bit strings of length 8? a) The set of bit strings that end with 00; the set of bit strings that end with 01; the set of bit strings that end with 10; and the set of bit strings that end with 11. b) The set of bit strings that end with 111; the set of bit

### Union and Intersection of Sets

Create 2 sets. Set A will be the list of the 5 items you personally need to buy the most (essential items). Set B will be the list of 5 items that you want to buy the most ( fun stuff). List the items in set A and B and also list or state the items in the union and in the intersection of set A nad B Assume that the prices of

### Solving a Combinations Problem

Mrs. Jones had some white paint and some green paint, and a bunch of wooden cubes. Her class decided to paint the cubes by making each face either solid white or green. Juan painted his cube with all six faces white. Julie painted her cube solid green. Herman painted 4 faces white and 2 faces green. How many cubes could be paint

### Abstract Algebra : Permutations, Binary Operations and Mappings

Consider a non-empty set A. Prove that S(A) is closed in (M(A),o). Meaning: "o" is the composition of functions which defines a binary operation on M(A), the set of all maps from A to A. You need to prove that the set of all permutations on A is closed under the composition.

### Abstract Algebra : Prove that if F is a Permutation on A

A-Prove that if F is a permutation on A, then F^-1 is a permutation on A. B-Prove that if F is a permutation on A, then (F^-1)^-1 = F

### Combinations

A representative of the Environmental Protection Agency wants to select samples from 10 landfills. The director has 15 landfills from which she can collect samples. How many different samples are possible?

### Set Operations

1. Write the following in roster form: Set N is the set of natural numbers between ten and sixteen 2. Express the following in set builder notation: Z = {2, 3, 4, 5, 6, 7, 8, 9, 10} 3. For sets A and B, determine whether A = B, A is a subset of B, or B is a subset of A

### Interval Notation Question

Write the sets attached using interval notation. If the set is empty, write O. a) The intersection of D and C, where D = {x|x <= -3} and C = {x|x >= 2}. b) {x|x < 3 and x >= 4}

### Vertices, Nodes, Breadth-First Search Algorithm and Rooted Trees

1. Use the breadth first search algorithm to find a spanning tree for the following connected graph. Start with A and use alphabetical order when there is a choice for a vertex. 2. For the following rooted tree, identify the following: (a) Which node is the root? (b) Which nodes are the internal vertices? (c) Is th

### Combinations Expansion Subsets

1. The coefficient of x^7y^2 in the expansion of (2x-y)^9 2. How many subsets of {2,3,5,7,11, 13, 17,19,23) contain four numbers? 3. If a committee varies its meeting days, how many meetings must it schedule before we can guarantee that at least two meetings will be held on the same day of the week?? 4. How many differe

### A binary relation R is defined in terms of a given matrix. Determine whether R is a partial order. If it is, draw its Hasse diagram.

For the set A = {a, b, c}, let R be the relation on A which is defined by the following 3 by 3 matrix M_R: ---------------------------------------- Row 1: 1 0 1 Row 2: 1 1 0 Row 3: 0 1 1 ----------------------------------------- Determine whether R is a partial order. If it is, draw its Hasse diagram.

### How Combinations Are Determined

A woman has 9 close friends. (a) In how many ways can she invite five of these to dinner? Explain/show work. (b) Repeat part (a) with the added stipulation that two of her friends do not like each other so that if she invites one of them she cannot invite the other. Explain/show work. (c) Repeat part (a), assuming t

### Show that a set of real rational functions is a field.

NOTE: In this description, R represents the symbol for the set of real numbers. I couldn't find a way to type or copy the correct R symbol for the set of real numbers. Also, the parentheses in R(x) is used to distinguish the ring R(x) of rational functions from the ring R[x] of polynomials. Show that the set R(x) of rational

### Graphs, Digraphs, Trees and Forests

I am posting one problem from Exercise 2.2, I need answer for 2.9. I am posting another question from Exercise 3.1: Problem 3.2.) Prove that a graph G is a forest if and only if every induced subgraphs of G contains a vertex of degree at most 1. Problem 3.1) Draw all forests of order 6. See attached file for full pr

### Several problems on annuity, compound interest, permutations and combinations are given to solve.

1. Find the effective rate of 8.5% compounded semianually. 2. Tony invested some money at 10% compounded quarterly at the end of three years his investment had grown to \$2488.05. Find the initial investment. 3. Find the amount of an annuity with \$2500 deposited quarterly at 8% for four years. 4. A sinking fund is e

### 14 questions: probabilities, expected value, combinations/permutations

I need help in showing how the attached problems are worked out. Thanks ... 1. During the last hour, a telemarketer dialed 20 numbers and reached 4 busy signals, 3 answering machines, and 13 people. Use this information to determine the empirical probability that the next call will be answered in person. 2. If you ro

### Combinations and Permutations

1) Identify each of the following 1) as a permutation or combination and 2) as with or without replacement: a) Social security numbers b) Books in your backpack c) Numbers chosen for the "Big" lotto d) The cards in your hand for a card game e) Lunch chosen by a student from the cafeteria menu 2) A

### Statistics Problem Set

See attached file for full problem description. 1. If A &#61645; B and B &#61645; C, what can you conclude? Why? What if A &#61644; B and B &#61644; C? If A &#61645; B and B &#61644; C? 2. Write down all possible subsets of {a, b, c, d} 3. Without writing them down what are the number of subsets of the set A = {a, b,

### Permutation or Combination Calculations

For each question determine if the situation is a permutation or combination and if it is with or without replacement, then determine the answer. 1 Identify each of the following 1) as a permutation or combination and 2) as with or without replacement: a) Social security numbers b) Books in your backpack c) Numbers chosen

### Combinations of Ten People

A committee of size seven is to be selected from a group of ten people. In how many ways can this be done?

### Discrete Math : Combinations, Permutations and Probability (25 MC Problems)

This test consists of 25 equally weighted questions. 1. Given a two-step procedure where there are n1 ways to do Task 1, and n2 ways to do Task 2 after completing Task 1, then there are _________ ways to do the procedure. a. n1 + n2 b. n1 log n2 c. n1 * n2 d. n12 2. How many bit strings of length 10 begin with 1101? a.

### Combinations, Permutations and Cycles

How many elements of order 5 are there in S_8? - I think there are 8! / 3!5! = 56 ways to order the elements in the cycle but how many of order 5 are there? keywords: S8

### Permutations and Disjoint Cycles

Let b be the permutation (1 2 3)(4 5 6 7)(8 9 10 11 12 13) what is b^99 as a product of disjoint cycles. -I know b^99=b^3 but I'm a little confused on the disjoint cycles part.

A license plate in a certain state consists of a number followed by three letters followed by two additional numbers in the pattern #LL L##. How many possible license plates are there in this system?

### Combinations of Pairs of Slacks

Suppose you have 10 pairs of slacks from which to choose. How many different ways of selecting a pair of slacks do you have during a period of seven days?

### Direct Products, Permutations and Orders of Elements

Let a be the permutation (1 2 3) in A_4. What is the order of the element (3, 7, a) in the group U(10) direct product Z_42 direct product A_4.

### Combinations

2. A seven-person committee composed of Adam, Betty, Cameron, David, Edward, Fritz, and Grace is to select a chairperson, secretary, and treasurer. How many selections are there where Betty is the chairperson, and Adam and Edward are not officers? 12 20 24 210 None of the above