UMBC CMSC203, Discrete Structures, Fall 2010

News Archive

• [Tue Dec 14 13:25 2010]
  The regularly scheduled final exam is on Tuesday, December 21, 10:30am to 12:30pm in Sondheim 109.

• [Tue Dec 14 13:25 2010]
  Here's a better answer to Question 4e of the Spring 2009 Final Exam. This answer uses linearity of expectations which makes the calculations a lot simpler and explains why the answer comes to exactly 1.5: Spring2009_Final_Q4e.pdf.

• [Fri Dec 10 12:40 2010]
  Answers to all of the questions on the Spring 2010 final exam: CMSC203_Spring_2009_Final_Answers.pdf

• [Thu Dec 09 12:05 2010]
  As promised, here's the set equivalence proof as shown in class: Spring2009_Final_Q1.jpg. Some people requested that I post the other solutions. I will do this by Friday, because I need to edit the answers.

• [Thu Dec 02 07:35 2010]
  A make-up final exam will be held on Tuesday, December 14th, 10:00am – 12:00pm in ITE 229.

  Students who want to take the make-up exam must notify Prof. Chang by email by noon on Monday, December 13th. This is so the right number of copies can be made.

  The regularly scheduled final exam will definitely be held on December 21st. Taking the make-up final is completely optional.

• [Thu Dec 02 07:35 2010]
  It was brought to my attention that some of the grades on the Blackboard site were incorrect. The problem is that some of the homework assignments are out of 30 points and others are out of 40 points. In particular, Homeworks 6, 7 , 9, 10 and 11 were configured to have a maximum of 30 points, but were really out of 40 points.

  This has been fixed.

  The result is that your "weighted total" number dropped a couple of points. (E.g., if you had 35 points in HW11, Blackboard previously treated it as 35/30 = 117% but is really 35/40 = 87.5%). The effect is that your "weighted total" score might have dropped a couple of points.

• [Thu Dec 02 07:35 2010]
  Homework 13 posted.

• [Tue Nov 30 21:50 2010]
  I keep forgetting to put up the sample space for the Monty Hall problem.

• [Tue Nov 30 21:50 2010]
  Long before there was an Xbox, Wii or even a Gameboy, kids wasted time playing Dungeons & Dragons and became familiar with the Platonic solids. (There's a 4-sided die in the picture.)

• [Tue Nov 30 21:50 2010]
  When lectures get too boring, you should doodle like this.

• [Tue Nov 30 21:45 2010]
  Reminder: Quiz 5 is on this Thursday, December 2, and will cover simple probabilities and Bernoulli trials, but will not include random variables, expected value or conditional probabilities. Those topics will be covered in the final exam.

• [Tue Nov 30 21:40 2010]
  Correction on Question 2b of Homework 12: the word "conditional" should be deleted.

• [Tue Nov 23 11:40 2010]
  Note: Homework 12 has only 2 questions (with multiple parts). It used to have a third question on relations, but we didn't get to relations in lecture today. So what used to be the third question will make a reappearance in Homework 13.

  Oh, and Homework 12 isn't due until Thursday, December 2nd (not Tuesday).

• [Tue Nov 23 00:25 2010]
  Homework 12 posted.

• [Tue Nov 16 12:51 2010]
  Reminder: Quiz 4 is on Thursday 11/18. The topic of the quiz is counting.

• [Tue Nov 16 12:00 2010]
  Homework 11 posted.

• [Wed Nov 10 07:03 2010]
  Homework 10 posted.

• [Tue Nov 02 12:30 2010]
  This is a reminder that Quiz 3 is on Thursday 11/4.

  There will be one question on proof by induction. It will be of the numeric variety.

  As with all of the homework questions on proof by induction, you will be asked to:

  Clearly indicate using complete English sentences:

  1. what you are allowed to assume from the induction hypothesis,
  2. what you need to show to establish the induction step, and
  3. which steps of the proof uses the induction hypothesis.

  Responses that do not include well-written English sentences that clearly explain your proof will receive a grade of no more than 50%.

  I noticed while grading the midterm exam that some of you consider the instructions to include complete English sentences to be "optional".

  Well, they are not.

  If you think that most of the time that professors are just bluffing and they wouldn't give a 50% grade on an answer that is essentially correct except it is missing some English sentences, you might be right.

  HOWEVER, I am telling you ahead of time that this time I am NOT bluffing and I will follow through with the 50% (which, by the way, is 3.5% of your total grade for the class).

  See, I can't bluff all the time, then no one would believe me. So, you guys are "it", but I'm telling you ahead of time, so there will be no surprise. You'll have the full 30 minutes on 1 question. You will have enough time to write complete English sentences.

• [Tue Nov 02 08:05 2010]
  Homework 9 posted.

• [Tue Oct 26 09:55 2010]
  Homework 8 posted.

• [Tue Oct 12 07:47 2010]
  Homework 7 posted.

• [Tue Oct 05 12:01 2010]
  Homework 6 posted.

• [Thu Sep 30 16:11 2010]
  Updated "Equivalence Proof" with a set theoretic example.

• [Tue Sep 28 09:52 2010]
  Homework 5 posted.

• [Tue Sep 21 09:42 2010]
  The Computer Science Help Center is now open. Some of the tutors are listed as able to help out for CMSC203. Please consult the Help Center schedule .

• [Tue Sep 21 09:42 2010]
  Homework 4 posted.

• [Thu Sep 16 11:55 2010]
  Here are the notes on proof methods.

• [Wed Sep 15 22:20 2010]
  The Blackboard site for this class is now available. Your grades will be posted there. (This is the only feature of Blackboard we will use.)

• [Tue Sep 14 09:24 2010]
  Homework 3 posted.

• [Thu Sep 09 11:47 2010]
  Added hint for Question #1 in Homework 2 that the smallest vertex cover has 10 vertices.

• [Tue Sep 07 07:36 2010]
  Homework 2 posted.

• [Thu Sep 02 09:35 2010]
  Course Description and syllabus handed out on the first day of class are available in PDF.

• [Tue Aug 31 11:47 2010]
  I posted a write up on the pizza cutting procedures discussed in class today: pizza-cutting.pdf. In the mathematical literature, this is actually called "Cake Cutting," but I wrote this up a couple of years ago with pizza. (Yes, there are entire books written on this topic, for example this one.)

• [Tue Aug 31 08:28 2010]
  Homework 1 posted.

• [Mon Aug 30 17:25 2010]
  The first quiz is on Thursday, September 23. Mark your calendars with the dates of the in-class quizzes and exams from the syllabus!

• [Mon Aug 30 17:25 2010]
  Note: the drop date has been moved earlier this semester. September 14, 2010 is the last day to drop a class without a grade of "W".

• [Mon Aug 30 16:45 2010]
  Web page up.