This is a simple question but is the only difference between necessary and sufficient assumption is that the sufficient is stronger than the necessary? While you're still identifying the gap in the argument, and then tailoring the answer to fill that gap, the sufficient guarantees the conclusion, whereas the necessary is just the baseline of what should be true to make the conclusion true?

@Kevin_Lin yes it does, thanks so much!

If an original argument has a necessary and sufficient condition, does changing it to the contrapositive flip which condition is which?