讲解CIT 592、Python,Java,c/c++程序设计辅导、辅导data留学生 解析R语言编程|解析Java程序

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CIT 592 Spring 2020 Homework 1
YOUR NAME HERE
YOUR PENN EMAIL HERE
1. [10 pts] Jack and Jill want to rent separate apartments on the third floor of a new building
by the river. The building has nine apartments available, numbered 301, 302,. . . , 309. The
odd-numbered apartments have a river view, and the even-numbered apartments do not. Jill
will only rent an apartment with a river view, and Jack does not care about the view.
How many distinct possibilities exist for the pair of apartments they end up renting?
Solution.
YOUR SOLUTION HERE
2. [10 pts]
(a) A number n ∈ N is called perfect if the sum of all of n’s factors other than n itself is equal
to n. For example, 6 is perfect because its factors are 1, 2, 3, and 6, and 1 + 2 + 3 = 6.
Prove that there are no perfect prime numbers.
(b) Let m, n ∈ Z
+, and suppose that m is a factor of both n and n + 1. Prove that m = 1.
Solution.
(a) YOUR SOLUTION HERE
(b) YOUR SOLUTION HERE
Homework 1 CIT 592 2
3. [10 pts] n ≥ 2 distinguishable Hogwarts students participate in Professor Snape’s experiment.
Each student is given one of three concoctions: potion A, or potion B, or a mixture of the two.
Snape makes sure to give a different concoction to each of Harry and Hermione. In how many
distinct ways could Snape have distributed his concoctions?
Solution.
YOUR SOLUTION HERE
4. [12 pts] Prove that for all odd integers x and y we have 8 | x
2 − y
2
.
Solution.
YOUR SOLUTION HERE
5. [8 pts]
(a) Give an example of three distinct (no two are the same), nonempty sets A, B, C such that
• there are elements that are common to A and B;
• every element of A that is also in B must also be in C;
• there are elements in A that are not in C.
(b) Let A be a finite set such that {∅} ∈ A and {∅} ⊆ A and |A| = 2. List all the subsets of
A. Justify your answer.
(c) Consider the sets A = {1, 2, 3}, B = {x
2
| x ∈ A}, and also C = {x+y | x ∈ B and y ∈ A}.
List the elements of A ∩ C. Show your work.
(d) Give examples of three sets A, B, C ⊆ {1, 2, 3, 4, 5, 6, 7} such that A and B are disjoint,
A \ C = {1, 3, 7}, B ∪ C = {2, 4, 5}, |A| = 5, and B \ C 6= ∅. Show your work.
Solution.
(a) YOUR SOLUTION HERE
(b) YOUR SOLUTION HERE
(c) YOUR SOLUTION HERE
Homework 1 CIT 592 3
(d) YOUR SOLUTION HERE
6. [10 pts] Let A = {2, 3}, B = {3, 4}, C = {2, 3, 4}, and S = A × 2
B×2
C
. Answer each of the
following questions. Explain your answers.
(a) (2, {(2, {2})}) ∈ S ?
(b) (2, {(3, {4})}) ∈ S ?
(c) (2, {({4}, 4)}) ∈ S ?
Solution.
(a) YOUR SOLUTION HERE
(b) YOUR SOLUTION HERE
(c) YOUR SOLUTION HERE
7. [6 pts] EXTRA CREDIT CHALLENGE PROBLEM
We have a bag filled with 110 marbles, where 55 of them are blue and 55 of them are red. Every
turn, we remove 2 marbles from the bag. If the two marbles are of the same color, we remove
the two marbles but add a red marble into the bag. If the two marbles are of different colors,
we remove the two marbles and add a blue marble into the bag.
What is the color of the last marble in the bag?
Solution.
YOUR SOLUTION HERE

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