Course Syllabus

CMSC 250

Discrete Structures


Instructors & Lecture Times / Hours


(Tentative) Course Schedule


We include textbook chapters for your convenience.


Wedn Jan 24 classes start (discussion sections and graded math quiz)


Jan 25 1.1 prop logic intro


Jan 30 1.2 logic gates

Feb 1 1.3 equivalences and satisfiability


Feb 6 1.4 pred logic intro

Feb 8 1.5 nested quantifiers


Feb 13 1.7 Proof

Feb 15 1.8 Proof


Feb 20 2.1-2 Sets

Feb 22 2.3 Functions


Feb 27 2.3  Cardinality

Mar 1 2.4 Summations



Wedn Mar 7 EXAM I (6-8pm; covers up thru Feb 22)

Mar 8 4.1 Mod arithmetic


Mar 13 4.3 Primes and GCD

Mar 15 4.3 Euclidean algorithm


Mar 27 5.1 Ordinary induction

Mar 29 5.2 Strong induction


Apr 3 11.1 and 5.3 Trees; Structural induction

Apr 5 Constructive induction


Apr 10 Induction wrap-up

Apr 12 6.1 Counting



Wedn Apr 18 EXAM II (6-8pm; covers up thru Apr 10)

Apr 19 6.2 Pigeonhole principle


Apr 24 6.3 Permutations and combinations

Apr 26 6.3 cont’d


May 1 6.4 Binomial theorem

May 3 9.1 Relations


May 8 9.5 Equivalence relations



Discussion Sessions, Tutors, Graders, Office Hours

Here's a spreadsheet with the assignments of tutors ("teaching TAs")and graders to sections, as well as our office hours. If there is ever any need for a cancellation or a trade of office hours, you will be notified through ELMS and the update will also be reflected on that sheet.

Claiming an Excused Absence

If you were absent from a quiz or midterm and your absence is excusable as per University Regulations (see below), please e-mail Jason Kuo so that he can make sure the relevant ELMS grade box is blank. For quizzes, this means that that particular quiz will be excused and won't be a zero that counts against your grade. For midterms, this means that your name will be added to a list of people who will be needing a makeup. A Doodle poll will then be distributed asking people of their availability on various days and times so that we can find a single room to accommodate everyone's makeup needs.


Description of Assignments

  1. Weekly homework assignments. Those will be released on Mondays and are due the subsequent Monday at 11:59pmLate submissions are acceptable through the following Wednesday at 11:59pmwith a 50% penalty. Your responses will be compiled into PDF form and uploaded on ELMS. For information on how to create a PDF that will be acceptable for our purposes, see the section "Uploading your homework assignments" below.
  2. Discussion Session quizzes: Every Wednesday discussion session will have a (very short) quiz administered at the beginning (12 min) .  The first discussion  session, as well as a subsequent one around the middle ofthe semester, will have an algebra quiz. Your lowest 3 (three) non-algebra and your lowest two algebra quizzes will be dropped.
  3. Examinations. We will have 2 midterm exams and 1 final exam (see "Exams" section below). They will be written in pen (or pencil) and paper and will be handed out to proctors after the exam time. Closed book.


Major Scheduled Grading Events

  • Midterm 1:Wednesday 03-07, 6-8pm, campus rooms TBA
  • Midterm 2:Wednesday 04-18, 6-8pm, campus rooms TBA
    • Final: Date, time androoms will be announced by central scheduling mid-semester.



    The course staff reserves the right to slightly perturb the following percentages based on class performance, never more than 3% up or down.

    • Homework assignments: 1% each (#homeworks TBD, usually 9-11 hws per semester)
    • Discussion Session quizzes: 0.5% (half percent) each (1 per week, usually 12)
    • Midterm 125%
    • Midterm 225%
    • Final:Remaining credit after homeworks and quizzes (34% if there are 11 hws and 13 quizzes of which the bottom 5 are dropped - bottom 2 algebra quizzes and bottom 3 non-algebra quizzes)

    Here is how final scoreswill be calculated for our course (assuming that the final will be weighted at 34%):

    • Suppose that your score on quiz LaTeX: i is LaTeX: q_i, and your score on homework LaTeX: i is LaTeX: h_i.
    • Let's call your score on midterm 1 LaTeX: M_1 and on midterm 2 LaTeX: M_2.
    • Let's call your score on the final LaTeX: F

    Then, your final score is determined by the equation:


    LaTeX: {\color{green}{0.00625 \times \displaystyle \sum_{i=0}^{7}q_i + 0.01 \times \displaystyle \sum_{i=0}^{10}h_i}} + \\ {\color{magenta}{\max \big (}} 0.25 \times (M_1 + M_2) + 0.34 \times F,  0.375 \times {\color{blue}{\max (M_1, M_2)}}  + 0.465 \times F {\color{magenta}{\big )}}
    0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F ) 0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F ) 0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F ) 0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F ) 0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F ) 0.005 × i = 0 12 q i + 0.01 × i = 0 10 h i + max ( 0.25 × ( M 1 + M 2 ) + 0.34 × F , 0.375 × max ( M 1 , M 2 ) + 0.465 × F )

    Note that this equation has a max inside a max. Here's a plain English translation: Your quiz and homework grades are added up and weighted by 0.5% and 1% respectively. All this is represented on the left of the first max sign. Then, we have to weight your exam grades accordingly to add them to the quiz/homework grades to produce your score in the class. This is where the max comes to help you out. At the end of the semester, we will calculate your exam grade in two ways:

    1. Regularly, i.e we will weight your midterms and finals as is ordinary (25% and 34%).
    2. We will drop your lowest midterm and re-distribute its weight (25%) equally across your highest midterm and your final (so 12.5% each, for 37.5% and 46.5% respectively)

    Your final exam grade will then be the maximum of those two grades.

    University "Course-Related Policies"

    Starting with Fall 2016, the University has packaged certain campus-wide "course-related policies" into a single centralized webpage, which is traversable by navigating this link. Every course is required to link to these policies, which cover very important elements such as:

    • Excused absences (what are your rights, what are our responsibilities), including dates of projected religious observance.
    • Disability accommodations on campus
    • Code of Student Conduct and matters pertaining to Academic Integrity.
    • Grade contesting.
    • Mid-Term ("Early Warning") grades

    It is the responsibility of every instructor on campus to link to the course-related policies page from the course syllabus. Those policies are part of this (and any other) syllabus and you should familiarize yourselves with them! We further specialize the "course-related policies" by virtue of the following rules that affect midterms:

    • Midterm exam make-ups will be given only up to 1 (one) week after the scheduled date.
    • The following is the process according to which Midterm grade contests will be made:

    - Midterms are scanned and uploaded on Gradescope. Gradescope allows us to publish both the scores and the rubric used, 

    - Regrade requests are submitted by you electronically once the results are published. You will have time to submit a regrade request within one week from the release of grades.

    - VERY IMPORTANT: If from what you claim in your regrade request it seems you know LESS than we thought you can lose points. Here are two characteristic examples that really happened:

    (a) The problem asks for a prime between 50 and 60. The students answers 57 and gets a 0 (3 divides 57).The student's regrade request argues that 57 IS a prime and hence he deserves credit. He then LOST 5 points, since 57 is not a prime LaTeX: (57 = 3 \ast 19)

    (b) The problem asks for a quantifier statement that is true in the integers but not in the naturals.The student writes:

    (\exists x)(\forall y)[ y\ge x]

    This is incorrect- its true in \mathbb{N}The instructors had been incorrect in assuming it was a misread; the student proved to us that they knew less than what we thought.

    • Students needing ADS accommodations are requested to provide the instructor with the necessary ADS forms during the schedule adjustment period, detailed on this webpage as being the first 10 days of lecture.


    This semester, we have a required textbook. This textbook is:

    Kenneth Rosen,Discrete Mathematics and its Applications, 7th edition, McGraw Hill, ISBN-13: 978-0-07-338309-5

    However, we do not require that you purchase the 4th edition of the book new (the cost of the hardcover can go all the way up to $350 through online retailers like Amazon). Consult the University Bookstore for more.

    Uploading your homework assignments

    We only allow PDF format for the uploading of your homework assignments, whose description will also be supplied in PDF format, preparedwith the document preparation system\LaTeX.We can think of four different ways to submit your homework assignments:

    1. \LaTeX("lah-tech"; highly encouraged) The best way to submit your assignments is to edit the provided\LaTeXsource files (which have the suffix .tex)and then convert them to PDF using pdflatex. This is because of the ease, aesthetic quality and modularity of mathematical formulae with \LaTeXTo help you out with learning\LaTeX, we have included the well-known document "The Not So Short Introduction to "in our course materials (link to PDF). It has been observed anecdotally that people who learn\LaTeXtend to never, ever want to use another program to author documents ever again.
    2. Microsoft Word or Open/Libre Office(easy with simple text, tough with formulae): It is also possible to use your favorite office suite to write down your responses, but you would have to convert to PDF before submission, otherwise the system will not let you upload your response. Those programs tend to have very cumbersome and unwieldy, WYSISWYG equation editors, so we prefer\LaTeXto using those.
    3. Directly editing the PDF with a PDF program that allows it (very easy with simple text, virtually impossible with formulae): Some programs like Adobe Acrobat DC Professional (available for free to all students through Terpware) and Apple Preview in Macs allow for this, but we have not found an easy way for the inputting of mathematical formulae.
    4. Hand-Written scan: If you must submit a hand-written response, we kindly ask that you use an actual scanner to turn your response into a legible PDF. This University libraries link has a lot of information about scanning, printing and copying around campus; consult it if you're not sure where to use a machine capable of producing quality scans of handwritten documents. If you submit a hand-written response, it will have to be legible. If we cannot read your response to a question, we will not be able to grade it with anything above a zero!

    Excused absences for quizzes and midterm makeups

    • Quizzes. Students that were not present for a quiz because of an excused absence (see relevant section on excused absences) can have that quiz grade excused. This means that the quiz average of the student will be computed over those quizzes that they actually did sit for, minus their bottom 3 which will be automatically dropped by ELMS. In particular, we would like to stress that no make-up quizzes are offered.
    • There are make-up midterms. As stated in the specification of the campus-wide "Course-Related policies" above, a student whose absence from a midterm or final was excused, can sit for a make-up midterm within one week from the scheduled time of the actual midterm.
    • Make-up finals are also possible, once again within one week of the scheduled date of the exam.


    Here are some official tutoring services for you:

      • From the 7th of February onward, the Association of Women in Computing (AWC) will be offering free "drop-in" tutoring in AVW3165 for various courses, CMSC250 included. The followingare their days and hours:



    10:00am - 12:00pm


                1:00pm - 3:00pm


    10:00am - 12:00pm


                12:45pm -2:45pm


    12:45pm -2:45pm (AVW 3258)


    The AWC also offers one-on-one tutoring by request: please visit for more.

    • The Academic Success and Tutorial Services (ASTS) program offers complimentary tutoring for UMD students. To connect with a peer tutor for this course, sign up directly at For questions, contact Christal Dimas, Tutorial Coordinator for the Academic Achievement Programs (AAP) at or 301-405-4745.
    • The office of Learning Assistance Services, which is part of the Counseling Center of the University (link to their website), also offers free tutoring for UMD students. Their office is2202 Shoemakerand their phone# is301-314-7693. Their academic coaches can help with time management, reading, math learning skills, note-taking and exam preparation skills. They also offer practice midterms.


    Web accessibility

    Please navigate this official UMD accessibility link for the full spectrum of accessibility information in the UMD campus. ELMS-Canvas is highly tuned towards accessibility, offering automatic link checking, suggested color palettes, standardized HTML for screen readers, and so on and so forth. The course staff takes accessibility issues quite seriously; please e-mail us if you feel you would like some further assistance with accessing our course materials. Also, please go through this ELMS student orientation if you'd like some information about using the system.

    You are responsible for being in tune with our ELMS announcements. We suggest that you tune your ELMS settings to receive e-mails when we post new announcements.


    This syllabus is subject to changes at any time during the semester, and such changes will be announced to the students through ELMS. 

    Course Summary:

    Date Details Due