Question 21 is an inference must-be-true question.

It is fairly straightforward in application of the core curriculum lessons on logic.

So if you didn't get this question right, you really should have gotten it right on Blind Review

just by very carefully translating this out, translating out each answer choice.

So, okay, so I'm going to show you how to do that here.

So here, we know the relationship is that of a most relationship.

So most of what?

Well, students, but it's students modified, right?

Students who took Spanish 101 at the university last year.

So let's just call them students, right?

Because that actually happens to be the set of students that we talk about later on in the question stem anyway.

Students who took Spanish 101 at the university last semester.

What about those students?

Well, most of them attended every class session.

So just a big A for attended every class session.

You just got to sort of remember A stands for attended every class session.

So now let's let me ask, what is the negation of this, right?

Is it attending zero class sessions?

Well, no.

If you think it's attending zero, then you got to review your lessons on negation.

That's not how logical negation works.

It just means not attending every class session.

You could have missed one class session and that you would have not attended every class session, right?

So however, each student who received a grade of, so you got to hear this grade thing, right?

They're carving out a range of grades, a grade lower than B minus.

That does not include B minus.

It's lower than B minus.

So B, right?

Starting from, I'm sorry, no, that is not lower than B minus.

C plus is the first grade lower than B minus.

So from C plus and down, right?

So who received a grade lower than B minus, right, missed at least one class session.

See, this at least one class session missed at least one class.

That's their way of telling you the negation of this, right?

Each student who received a grade lower than B minus missed at least one.

So each is our logical indicator.

So if you see the grade of lower, right, lower than B minus, then what?

Then you missed at least one.

Now, how do you want to represent miss at least one class session using the terms that we already have, right?

That's just an A slash.

That's just a not attended every class session.

So now you can run the contrapositive on this to hook this up, right, to hook this up.

Because you can't take the contrapositive on, there's no contrapositive at most, right?

So you want to run the contrapositive on this.

So if you attended every class session, in other words, if you didn't miss at least one class session,

then what? Then you didn't, then you have to negate this.

You didn't get a grade of lower than B minus, which means, well, you got a grade of B minus, right, B minus or higher, right?

That's the, this bit is a contrapositive of this bit, right?

So once you get to this, once you get to this, right, then this just becomes from our exercises and drills,

A most B, right, all B's are C's, therefore what?

Well, therefore A most, right, the B carries through A most C.

So what's our A element?

Well, that's just the students that we're talking about, the 101 students.

And our C element, right, our C element's got B minus or higher, okay?

Which, I mean, at this point, it's just a matter of matching, right, E is right.

Now I think, what is this, C is very attractive because it, like, you kind of run down the list,

you hit C and you got to get past this hurdle, right, because it says pretty much the same thing.

Most students, more than half, that's the same thing, right, receive the grade of higher than B minus versus a grade of B minus or higher, right?

That's the bit that makes C wrong.

It's not higher, it's not just the or, right, it's this or this.

You can't just have, like, oh, not this and just this.

That's not, that's not a valid inference, right?

I mean, the others are, at least some of the students receive a grade of A minus or, I don't even know where the hell they get this stuff from.

like, missed one of this, like, A slash most lower than B minus, I don't know.

And this one, it's a sum relationship, at least one student who received a grade B minus or higher missed one or more classes.

That's not, like, if they said, you know, every student who received a grade of lower than B minus received, missed one class,

so then you can change this to a sum relationship, right, because if it's an all relationship, it implies a sum relationship.

So you can say some student who received a grade lower than B minus missed at least one class, but that's not, this is not, this is higher, right,

so I don't know where they got that from either.