"some" is too weak. "some" only becomes valid when it teams up with an "all."

Some + all → VALID

Some + most → invalid

Some + some → invalid

For Most before Most:

The TRICK: same starting set = guaranteed overlap = valid. Different set in a chain = no overlap guaranteed = invalid.

Valid example:

You'll see that class is the same starting set*:

class* —m→ soccer (Most students in my class play soccer)

class* —m→ bikes (Most students in my class own a bike)

__________________

soccer ←s→ bikes (Some soccer players own a bike)

_____________________________________

Invalid example:

You'll see that there is no same starting set*:

class* —m→ soccer (Most students in my class play soccer)

soccer* —m→ injured (Most soccer players get injured)

__________________

class ←s→ injured (Some students in my class get injured)

All dogs eat. Mr. Kitten eats. Therefore, Mr. Kitten is a dog.

That's invalid. "All" is a sufficient condition indicator, so:

• Dog (A) = sufficient

• Eats (B) = necessary

The rule is Dog → Eats (A → B). Being a dog is enough to know something eats.

But eating is just the necessary side. lots of things eat that aren't dogs (cats, humans, goldfish). So when Mr. Kitten eats, all you've done is confirm the necessary condition. That doesn't trigger anything backward. You can't jump from "he eats" to "he's a dog."

The mistake in arrow form: you're treating B → A as if it followed from A → B. Swapping without negating = the necessity/sufficiency trap.

You flip AND negate both sides. So A → B becomes ¬B → ¬A. That's always valid.

The trap is when you flip WITHOUT negating — turning A → B into B → A. That's the sufficiency/necessity swap the lesson is warning about.

So for Gryffindor (G → B): "no bravery, no Gryffindor" (¬B → ¬G) is legit, but "brave, so Gryffindor" (B → G) is the mistake. Just remember: swap + negate = good, swap only = trap.

screenshot and upload to an AI bot to remake it for you in a pdf version. I used Claude. Worked perfectly.

congratulations! how long did you study for? any advise to future test takers?