You are understanding it all correctly. Good work!

Hello! I completely understand that it can be frustrating to feel like you're not making progress. I recommend devoting some time to figuring out what is leading to wrong answers. Watching explanation videos and keeping a Wrong Answer Journal are both great ways to figure out where you are going wrong and what adjustments you can make. Doing more and more questions is not always as effective as taking a step back and looking at your process. Good luck!

Hi Morgan! B says "Larocque never signed any of his paintings." We do know that this painting is unsigned, so I can see what is attractive about answer choice B. However, this does not go far enough to attack the idea that the painting was written by one of his students. Remember, the question stem asks us to find the answer choice that most weakens the argument.

C does that better. C says that just like Larocque, no painting recognized by one of his students contains orpiment. This attacks the conclusion (which is supported by a premise that no known painting from Larocque contains the pigment). C says the same is true for his students.

I hope this helps!

Hi! We need to understand that the necessary assumption is that explanations of the basics of composting must include an explanation of the difference between hot and cold composting.

What D does is it swaps that idea. D says that everyone who understands the difference between hot and cold composting understands at least the basics of composting.

This should give us pause because although we know that this hot/cold understanding needs to be PART of our understanding, it doesn't get us the whole way there. This is wrong because somebody could know this but be missing all other knowledge about composting.

A final note, D does not commit a sufficient necessity flaw. That is the "improved" version of D that J.Y. talks about briefly! Hope this helps.

Hi! Bi-conditionals here can be identified by the indicator "A if and only if B." Here we have a "is brought about only by" which is the same thing in different words. But to get to this certainty, we need to be sure about the second half of the statement: "One knows that there are no similarly structured societies not subject to those factors, and no societies that, though subject to those factors, are not so structured." If all that is true, then we get the certainty of the bi-conditional.

I hope this helps, if you respond with a more specific area of confusion I'm happy to explain further.

Exactly right! A assumption that if negated wrecks the argument is going to be necessary. The same isn't true for sufficient assumptions.

Hello! D is wrong because the altitude at which some of the effects of oxygen deprivation became apparent is irrelevant to the conclusion. We are concerned here with different parts of the brain- not with when oxygen deprivation hits the climbers.

Hey @ericdanielsilvagomez518 .Redoing questions can be beneficial strategy-wise, so long as it isn't so recent that you immediately remember the answer. What we do try to preserve is questions from certain PTs to keep those as new to you as possible. I wouldn't worry too much about redoing questions in drills!