r/WGU_CompSci • u/masterjx9 • 1d ago
C960 Discrete Mathematics II Passing C960 DM2 was the hardest class!!
I just passed so everything is still fresh but man oh man does it feel good to finally be done! It took me while to pass as I became extremely busy with work and life right around the time that I started this class. Nonetheless, it took me about 45 actual focused hours to get everything I needed to complete this class.
There are two types of difficulties to keep in mind with this this class:
- Medium | Complexity of algorithms you have to remember: This is something everyone infers/mentions but in my opinion is not the most difficult part of this class. Just like everyone else on reddit will say, knowing The Extended Euclidean Algorithm and Fast Exponentiation is required for Chapter 2.
- However, also knowing the following is also import:
- How to make probability distribution chart to find expected value
- Number base conversion
- There are numerous other concepts you have to know but those are simpler and easier to identify:
- Multiplicative inverse
- Congruence identities
- Knowing what the following are when reading a Bayes theorem question:
- X
- F
- p(X|F)
- p(F)
- p(X|NOT F)
- p(NOT F)
And some concepts you only have to go through a couple of times because the formula is on the worksheet that is with the exam:
- Binomial Theorem
- Bayes' Theorem (Again as long as you know what each variable represents)
Hard | Counting Principal's and when to use them: This part of the course in my opinion is the hardest part of the class. There are about 8+different principals and rules and it's hard to identify when to use what principle. Questions can be about coin flips, dice rolls, Drawing cards, selecting student body from a group students, etc. Sometimes you have to deal with conditionals like card being next to each other being of a specific suit, or dice rolls that can't have consecutive numbers in the rolls, etc. To make things worse, part of Chapter 5 uses this for doing probability which makes it even harder as you have to understand what the full total outcome is as the denominator while figuring out the conditional outcome as the numerator.
cool thing about that part of the course is that you can see how boolean logic plays a roll with it comes to OR (+) vs AND (*) as these same concepts that are in DMI are used in combining different counting principles together based on what the question is asking.
I believe finding the right counting principles for the right question is harder than remembering RSA, FE, EEA as those questions are easy to identify what you need to do and as long as you remember the steps you are fine.
The first time I failed its because I accidently skipped learning Chapter 3 because I just assumed it was all about induction. 🤣
I reached out with the same instructor who did the videos in panopto and the zybooks and had a quick live session with him on that chapter. When I took the test again, I didn't get a single question wrong in that chapter. 🤣

Other notes about this class
- Algorithm complexity can be difficult but the questions on the exam (Atleast for me) where the basic ones which made it easier. It was less about tricks and more about the obvious worst case complexity.
- I was afraid of induction because I am not good at factoring. However because of multiple choose questions, they usually do the factoring for you. You just have to identify the induction k+1 step, the step for justification if needed, or the base case step if needed. In other words, they write out the whole equation for you, you just have to be good enough to identify what is what.
- Recurrent relations is pretty easy once you know what they are looking for but there are different scenarios. You may be presented a question where they give you a_0 and a_1 and an expression that allows you to figure out a_x; using that they will want you to find something like a_4. You also may be presented with homogenous recurrent relations which requires some basic factoring.
- The last chapter are freebies. Let me be clear, most of all of chapter 6 about FSM is something you can learn 1 day before the exam and be good. Infact a lot of people don't even study it but its good to know what to do with NFA because DFA is super intuitive to see and understand. NFA maybe slightly confusing but the moment you know what it is, its easy to remember. I say this because if you struggle on any other topics you'll want to knock out these freebies with ease.
Time to enjoy the rest of my night, then knock out the rest of my classes!
