553.420/620 (Fall 2023)

553.420.01, 553.420.02, 553.420.03, 553.420.04 & 553.620.01
by Dr. Josué Tonelli-Cueto
at the Johns Hopkins University

Basic Information

Course Title: Probability Taught Sections: 553.420.01 & 553.420.02
Instructor: Dr. Josué Tonelli-Cueto 553.420.03, 553.420.04 & 553.620.01
Office: Wyman N416
Office Hours: Monday, 5.00 - 7.00 pm Instructor of
Both in office and by Zoom Remaining Sections: Dr. Zachary M. Pisano
List of TAs: Gabe Gormezano [Head TA]
(w/ Office Hours) (Friday, 1.00 - 3.00 pm) [online]
TJ Bai Zhihan (Bella) Xia
(Tuesday, 4.00 - 6.00 pm) (Friday, 10.00 am - 12.00 pm)
Chase Feng Sujin Lee
(Tuesday, 9.00 - 11.00 am) (Tuesday, 1.30 - 3.30 pm) [in-person]
Ziling (Cecelia) Chen [Grader] Zihan (Travis) You [Grader]
(Wednesday, 10.30 - 12.30 pm)
online office hours through Zoom in-person office hours at Room S425 of the Wyman Park building

Instruction Information for 553.420.01 & 553.420.02

Days: Monday & Wednesday Place: Shaffer 304
Times: 1:30–2:45 pm
TA Sessions (on Thursdays)
553.420.01's TA: Zhihan Xia
553.420.01's Time: 9.00 – 9.50 am 553.420.01's Room: Maryland 202
553.420.02's TA: Gabe Gormezano
553.420.02's Time: 12.00 – 12.50 pm 553.420.02's Room: Shaffer 302

Instruction Information for 553.420.03, 553.420.04 & 553.620.01

Days: Monday & Wednesday Place: Krieger 170
Times: 3.00 – 4.15 pm
TA Sessions (on Thursdays)
553.420.03's TA: Chase Feng
553.420.03's Time: 1.30–2.20 pm 553.420.03's Room: Hodson 315
553.420.04's TA: Sujin Lee
553.420.04's Time: 3.00 – 3.50 pm 553.420.04's Room: Krieger 304
553.620.01's TA: Sujin Lee
553.620.01's Time: 3.00 – 3.50 pm 553.620.01's Room: Krieger 304


The description of the lectures is approximate. It can vary depending on the section.

Lecture 1 (Aug 28)

Lecture 2 (Aug 30)

Lecture 3 (Sep 6)

Lecture 4 (Sep 11)

Lecture 5 ()


The course will be based mainly in the following two books:

  1. Sheldon M. Ross. Introduction to Probability Models. Academic Press, 2014.
    doi: 10.1016/C2012-0-03564-8
  2. Gabe Gormezano. Intuition to Probability. Draft. (Available on Canvas).


The grade in this course will depend on homework, three midterm exams and one (compulsory) final exam according to the following formula:

\[\frac{20\,HW+25\,ME_1+25\,ME_2+30\,FE}{100}\in [0,100]\]

where $HW\in [0,100]$ is the grade on the homework (for which the lowest homework score is dropped), $ME_1\in [0,100]$ is the grade on the 1st midterm exam, $ME_2\in [0,100]$ is the grade on the 2nd midterm exam and $FE\in [0,100]$ is the grade on the final exam. Note that each one of these grade is a numerical scale from $0$ to $100$.

Once the numerical grade is computed, this will be converted to a letter grade as follows:

A+ $\geq 97$ A $\geq 93$ A- $\geq 90$
B+ $\geq 87$ B $\geq 83$ B- $\geq 80$
C+ $\geq 77$ C $\geq 73$ C- $\geq 70$
D+ $\geq 67$ D $\geq 63$ D- $\geq 60$
F $< 60$

These cutoffs may be lowered to reflect the instructors’ perception of the courses’ difficulty.


There will be 12 homework assigments, which you should complete and submit through gradescope.


To receive full credit for an assignment, you must show clearly and explain your work on all homework problems unless otherwise noted in the problem. Moreover, you have to submit the completed assignment by the due date/time to receive full credit for your work. However, if you submit within the first 24 hours after the deadline has passed, you will still receive 80% of the credit. After this 24-hour grace period, no partial credit will be given.

You are responsible for ensuring that gradescope correctly processes your submission, and that your work is both clear and legible. Illegible work will not be graded. Moreover, you may receive a score deduction if you do not correctly tag the individual problems in your submissions.


There will be two in-person midterm exams and one compulsory in-person final exam, which must be taken to pass the course. To the extent possible, exams are non-cumulative; however, since this course builds on itself and introduces definitions and ideas continually you may be required to recall an idea from an earlier part of the course.

The midterm exams will not be held during normal lecture time, but on October 2 and November 7 at 7.00 pm in Maryland 110. The final examm will take place on December 19 at 2.00 pm in a room that will be specified. Each of the exams will be 75 minutes long.