18.600: Probability and Random Variables

Table of contents

  1. Course Info
  2. Realistic Prerequisites
  3. Subject Matter
  4. Course Staff
  5. Lectures
  6. Problem Sets
  7. Exams
  8. Resources
  9. Grading
  10. Advice to Future Students

Course Info

Class Size 200
Hours/Week 10.7 (71 responses)
Instructors Scott Sheffield
Overall Rating 6.4/7.0

Realistic Prerequisites

  • The content of 18.01 and 18.02 was occasionally helpful, particularly for double integrals.
  • Students thought the beginning part of the class went by very quickly for those without some previous exposure to probability and combinatorics.

Subject Matter

  • Students generally found the material to be foundational and a good balance between theoretical and applied.
  • The class includes a mix of proofs and intuitive explanations for concepts.
  • Many examples were given from finance and economics.

Course Staff

  • The professor and TAs were seen as approachable and accommodating.
  • The extension policy was very lenient.


  • Lectures were fast-paced and engaging. Most students found lectures useful for conceptual overviews of topics, while psets helped with deeper-level understanding and applications.
  • Lecture notes were seen as supplemental, and did not correspond exactly with lectures.

Problem Sets

  • Problem sets were challenging and required creative solutions. They usually included real-life background or context for course material.
  • Many students received help at office hours when they became stuck on specific problems.
  • Students generally spent 4-7 hours on each pset.


  • Exam problems were considered easier than pset problems. Many students were challenged by the time pressure.
  • Students found reviewing previous/practice exams to be very helpful, saying the exams were mostly similar to past exams, with a few curveball questions.


  • Many students did not use the textbook, but those who did found it useful.
  • Lecture slides and lecture recordings were available online and generally considered to be helpful.


  • Students considered grading to be generous and fair as well as transparent.
  • Approximately 60% of the class receives an A and 30% receives a B.

Advice to Future Students

  1. “Definitely go to office hours, it helps so much. Especially the instructor ones, the instructors for these classes have great stories and really like explaining the story behind the various concepts which is very cool.”
  2. “Practice exams and the story sheet are your best friend for exams, and the psets pretty much require collaboration.”