MATH/COMP 61: Section 3
Discrete Mathematics
Spring 2017


Old HWs and exams are available to be picked up in the main dept office if you need them to study for the final

TA Linfeng Liu will have a special office hour from 1-5pm on Monday, May 8 in case you have questions before the exam.

NO OFFICE HOURS Sunday, April 30. Tuesday May 2 will be a REVIEW session for the final hosted by TA Linfeng Liu during our regular class time. Bring your questions. There will be NO regularly scheduled TA office hours during reading and finals week. You can always email or directly if you want to meet someone in this timeframe.

NO CLASS Tuesday, March 14: University closed due to Snowstorm!

If you want them to study before exam 1: Graded HW4s are now available Friday until 5pm or Monday from 9-5pm in the Computer Science main office (Halligan 245). Tell the staff you want to pick up your comp61 HW4 and they have it for you.

Tufts has declared Thursday, February 9th a snow day! There will be no class. Whether or not there are office hours on Thursday evening will depend on how hazardous it is for TAs to walk to Halligan Thursday evening: please email to see if a TA is in Halligan before you decide to walk over in the snow on Thursday evening. Due date of HW3 is postponed to 9am on Monday, Feb 13th, either in my box in the main dept office, or under my office door.

This is Discrete Mathematics Section 3. If you are in a different section, it has a different instructor and a different webpage. While we are all using the same textbook and covering approximately the same material, we are not synchronized.

Instructor: Lenore Cowen
Office: Halligan 107A;;
Office Hours: TTh 10-10:30am or email me for an appt.
Lectures: TTh 10:30PM-11:45PM, Halligan 111A

TA: Linfeng Liu ( linfeng.liu at
Emails: ta61-03 AT
Office hours: Monday and Wednesday 3-4pm in Halligan 121

Undergrad TAs and Graders: Lily Liu, Isaiah Mindich and Xiaoyu Shi
Email: ta61-03 AT
Additional Office hours in Halligan 121: Sunday, 6-8pm (IM), Monday 6-8pm (XS), Tuesday 8-10pm (LL), Wednesday 6-8pm (IM), Thursdays 6-8pm (XS), Thursdays 8-10pm (LL)

Description: This class covers foundations of discrete mathematics and introduction to proofs. Topics include Propositional Logic, Sets, Relations and Functions, Counting, Graph Theory, and a little bit of Probability and Number Theory.

Textbook: We are using: Richmond and Richmond, A Discrete Transition to Advanced Mathematics, American Mathematical Society as our text.

Grading: Your grade is based on 3 exams plus a final, plus your hw as follows. Your grade is based on e1+e2+e3+f+f, except you get to drop the lowest of the 3 scores (final is 2 scores). Your hw can pull your grade up or down by a 1/2 letter (for example, A- can go to A or B+ or stay A-, based on your HW performance)

HW assignments are due at the beginning of class on the day they are assigned, but can be handed in up to 9am the next morning in the instructor's mailbox in CS dept headquarters (2nd floor in Halligan Hall), without penalty (Or slid under the door of room 107A if it is after hours, clearly marked with my name). Except for this short grace period you must get permission 48 hours in advance due to illness or extraordinary circumstance to hand in late hw without penalty. HW handed in late but not arranged in advance will be subject to a a stiff lateness penalty and/or graded only at the discretion of the instructor and the TA.

HW collaboration policy: It is ok to talk to the Instructor, TA or other students about HW problems, but the final form that you turn in for grading should be written by you alone using your own words. You should not be looking up hw solutions on the Internet. If you have substantially collaborated with other students on a problem, please acknowledge this at the top of your HW sheet, i.e. "I worked with Alex and Robin on problem 10". The write up still needs to be your own. In addition, proofs require careful english explanations-- no credit for correct answers with no justification.

Rough syllabus: (subject to change)

Please note: the material on Big O and graphs is not all covered in your text; we rely on handouts and lectures.

According to the Tufts block schedule, our final exam will be Monday, May 8th from 7-9pm in our regular classroom.


  • Homework 1: pdf file (due Tuesday, January 24)
  • Homework 2: pdf file (due Tuesday, January 31)
  • Homework 3: pdf file (due Thursday, February 9: Postponed to Monday, February 12 at 9am due to snow)
  • Homework 4: pdf file (due Tuesday, February 21)
  • Homework 5: pdf file (due Thursday, March 9)
  • Homework 6: pdf file (due Thursday, March 16)
  • Homework 7: pdf file (due Tuesday, April 4)
  • Homework 8: pdf file (due Thursday, April 13)
  • Homework 9: pdf file (due Thursday, April 13) And here are some supplementary Graph Theory notes for reference.
  • Homework 10: pdf file (due Tuesday, May 2)