Maybe this is just math not making sense to me, but I really can't understand this stim.

I read it as:

All students live in either P or W

38% of all students take at least 1 night class

29% of the students who take at least 1 night class live in W

How on earth did we come to the conclusion that 38% is an average? Is it not just,,, a percent? AKA a fraction of a whole and therefore not an average? And how did we decide that the 29% was of all the students, and not 29% of the 38%? I'm so confused </3

@mkim13 oh you're a gem, thank you!!

Having a hard time with #5, it's the only one I got wrong and the video isn't really helping.

I got /PR --> /MJ and MJ --> PR.

I know it's wrong but I'm not really sure how.

Am I confusing the necessary and sufficient? If I am, then with an "unless" statement, how can I tell which statement is the necessary and which is the sufficient? Help!!