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Combinatorics

Group Actions and Transitive Permutations

A) Show that if n is odd then the set of all n-cycles consists of two conjugacy classes of equal size in An b) Let G be a transitive permutation group on the finite set A with |A|>1. Show that there is some g in G such that g(a) is not equal to a for all a in A. (Such an element g is called a fixed point free automorphism) c

A television commercial for Little Caesars pizza announced that with the purchase of two pizzas, one would receive free any combination of up to five toppings on each pizza. The commercial shows a young child waiting in line at Little Caesars who calculates that there are 1,048,576 possibilities for the toppings on the two pizzas.

1. A television commercial for Little Caesars pizza announced that with the purchase of two pizzas, one would receive free any combination of up to five toppings on each pizza. The commercial shows a young child waiting in line at Little Caesars who calculates that there are 1,048,576 possibilities for the toppings on the two pi

Permutation Groups and Commutativity

Let Y=(u v/u^4=v^3=1,uv=u^2v^2) Show that a) v^2=v^-1 b) v commutes with u^3 c)u commutes with u d)uv=1 e)show that u=1, deduce that v=1 and conclude that Y=1

Functions and countable sets

(See attached file for full problem description with all symbols) --- 2.14 (I) Prove that an infinite set X is countable if and only if there is a sequence of all the elements of X which has no repetitions. (II) Prove that every subset S of a countable set X is itself countable. (III) Prove that if

Solutions Modulo congruences

In order to solve the congruence 2x + 6 ≡ 4 (mod 8), your friend Phil Lovett wrote down the following steps: 2x+6 ≡ 4 (mod 8) x+3 ≡ 2 (mod8) x ≡ −1 (mod 8) From here, Phil concludes that the solution set to 2x + 6 ≡ 4 (mod 8) is {x; x ≡ −1 (mod 8)}. (a) Is Phil's

Problem Set

(See attached file for full problem description) a) Determine the irreducibility of x20-11 over Q(set of rationals), and use it to prove or disprove that the ideal <x20-11> is a maximal ideal of Q[x]. b) Construct an integral domain R and an element a in R such that a is irreducible but not prime in R. c) Suppose that R is

Combinations and Permutations

11. A computer lab contains the following computers - a Hewlett Packard, a Compaq, a Sony, a Dell and 3 different models of Macs. How many different ways can the 7 computers be arranged so that the Macs are all together? (You may assume the computers are all in one line.) 12. A public pool employs 17 lifeguards of whic

Counting Problems and Trees

In one residence, cell phones, lap top computers and digital tvs are very popular among students. In fact, all of the students own atleast one of these items, although onlu 15 own all 3. Cell phones are the most popular with twice as many students owning cell phones as own lap tops. and digital tvs are still rare, since only hal

Trees - Counting Problems and Combinations

A Pasta bar has a build your own pasta option. On this option, the menu lists 4 types of pasta noodles, 6 different vegetable choices, 4 meat choices, 3 cheeses and 3 sauces. Each customer who orders this option must choose 1 type of noodle and 1 type of sauce. The customer can choose as many of the vegetables as desired and up

Permutations

Some boys come into a room and sit in a circle. Four girls come in and arrange themselves between 2 of the boys, that is , the 4 girls join the circle, but all sit together. If there are 2880 different circles that could be formed in this way, how many boys are there?

Negative Integers Proof : Denote by -P the set of all negative integers, i.e., the set to which the number m belongs only in case there is a member n of P such that m = -n. If the number m is in -P..

2. Denote by -P the set of all negative integers, i.e., the set to which the number m belongs only in case there is a member n of P such that m = -n. If the number m is in -P and Z is a number such that m<Z, then Z is not in P. If the conjecture is true, prove it. If it's false, prove that its false by counterexample or a proo

Functions, Enumeration Schemes and Bijection

Let f:Z+ --> Z be the function defined by... f(n) = {n/2 n even { -(n-1)/2 n odd ? n even; The following table indicates the enumeration scheme behind the definiton of the function. n .......... 7 5 312468... f(n)..... ?3 ?2 ?1 0 1 2 3 4... Show that f is a bijection. [You may assume basic facts about the

Max and min

(See attached file for full problem description) --- First: solve this problem. Second: check my answer. Third: if my answer is wrong or incomplete explain why. Find the absolute max and min of on [-8,8] My answer: On the interval [-8,8], f has an absolute max at f(0) = 0 and an absolute min at f(-8) = -14

Binomial Coefficients and Combinations

Four people select a main dish from a menu of 7 items. How many choices are possible: a) If a record is kept of who selected which choice (as a waiter would) b) If who selected which choice is ignored (as a chef would). Analyze this part by the number of different choices made.

Lebesgue Measurable Set

Let A be a set in R^n, we denote by A + x_o a parallel shift of A by x_o to A + x_o, A + x_o = { x : x = y + x_o, y in A}. Now, if A is a lebesgue measurable then show that 1). x_o + A is also lebesgue measurable 2). m(A) = m(x_o + A) Can someone check my answer and tell me if it is correct or not? My work: s

Lebesgue Measurable Sets, Compact Sets and Open Sets

If A is lebesgue measurable sets in R^n, bounded, then there is a compact set K_epsilon and an open set for every epsilon > 0 V_epsilon such that K_epsilon is subset of A and A is a subset of V_epsilon and for m(A-K) < epsilon m(V-K) < epsilon

Decision-Making Mathematics : Arranging Combinations of Sports Leagues Fixtures

In addition to each tem playing every other team in the league once at home and once away, the matches should be arranged such that: (1) each team only has one match per week (2) for any team no two matches should be successively at home or away (3) for any team no two successive matches should be against the same opposing

Power set and bijection

I have two small problems. I need all the work shown and in the second problem please answer in detail and NOT just yes or no. (See attached file for full problem description)