Propositional Logic Riddle, need help answering I have attached below a propositional logic riddle that I am having difficulty solving. It would be great if one of you could post a solution to this problem with some clear and concise explanations so I could understand what's going on. My professor isn't that great at teaching and I've looked at a bunch of videos and websites but am still for some reason having difficulty. Thanks a bunch! !enter image description here

Part a:

We assume Carla is a knight. That means she speaks the truth and Albert must also be a knight. However, now that Albert is a knight, he speaks the truth and says "Carla is a knave" which is a contradiction in the system. **Thus, Carla is a Knave.**

Part b:

Let's assume that Betty and Albert are _different_. Then there are two cases:

**Case 1** Albert is a knight and Betty is a knave: Since Albert speaks the truth, it is true that Betty is a knight, but that contradicts what we said about Betty being a knave. Not possible

**Case 2** Albert is knave and Betty is a knight: Since Betty speaks the truth, there must be two knights, however Carla is known to be a knave and Albert is assumed to be a knave which means there aren't two knights. Contradiction

Since they can't be different, either they're both knights or both knaves.