In PSA I have got all the easy ones wrong but then all the hard ones right??? My own brain is so confusing

So in any PSA questions, an answer with "only" is incorrect?

Can someone explain how to see the suff and nec in both answer B? just am missing how to see that with that wording

I was stuck for a while due to this simple mistake so I thought I would share in case anyone is in the same boat... Correct me if I am wrong, please!

The conditional indicator "no" (group 4) is not included in if something is a double-negative, and therefore cancels out it is simple the indicator of what "group" to use

For example, on Question 4 where it says, "There are no naturally occurring strains of wheat (NW) that have Rhizobium bacteria living in their roots." I kept getting confused on why the necessary condition wouldn't be negated as //NW which in turn would be NW... RB -> NW and it is because the conditional indicator word (no) is not used as a part of the double negative, you use it strictly to indicate and then use the following words to cancel out if required.

Can someone please help walk me through the second exercise? I was understanding everything up until this point but now I am confused on how to tell that that is invalid.

Are there any other places with more question types like this for practice?

I am also taking the August test and would love to be apart of this!

So in this and the last one, to put it very simply, if there is an arrow before the ←s→ or ‑m→ it is invalid? The ←s→ and ‑m→ must be first.

I am so confused about these without a video. I was understanding everything up to this point and this drill is making absolutely no sense.

It is refreshing to see others in the same boat. I am so burnt out this week and I think my fault was treating it like the week before a University final, cramming as much in last minute as possible. I am also planning on taking the October test too but wish good luck for all of us!

I keep getting these right but I actually have no idea how because I am thinking them through way less lol... I think overthinking these questions makes them wayyy harder

I have been so confused on the difference of NA and SA but the analogy that made me clearly understand is this...

A Necessary Assumption (NA) is like life support that keeps a patient alive. It gives the argument a chance to be true, but doesn't guarantee it, as other issues could still arise.

A Sufficient Assumption (SA) is like saying that as long as the patient is on life support, nothing can kill them. This guarantees the argument's conclusion, making it unbreakable.

In summary, an NA keeps the argument viable but not guaranteed, while an SA ensures the argument is conclusive.