Logical reasoning asks how a conclusion relates to the information supplied. In a must-follow question, a conclusion needs to be true in every arrangement allowed by the clues. Being plausible is not enough.
A small example
All amber tokens are round. Some round tokens are large. Must some amber tokens be large?
No. The large round tokens could all be blue. The statements allow amber tokens to exist without any being large. One valid counterexample is enough to show that the conclusion is not forced.
Notice what this answer does not say: it does not say that no amber tokens are large. It says the information is insufficient to require some overlap. Distinguishing false from not established is essential.
Keep outside knowledge separate
Logic questions often use invented categories so that familiar associations do not influence the answer. Even with ordinary words, treat the stated premises as the information for the puzzle.
If a problem says every marked box is sealed, do not assume every sealed box is marked. That reversed statement has not been supplied.
Represent the constraints
Use a short chain, a set diagram or a possible ordering when permitted. The aim is to make the relationship explicit. For example, A before B and B before C establishes A before C. It does not tell you where an unrelated D belongs.
Test the strength of your conclusion
- Does the conclusion use all, some, none or only?
- Did you reverse a one-way implication?
- Can you construct an arrangement where the clues hold but the conclusion fails?
- Is the question asking what must happen or what could happen?
These checks are useful across syllogisms, ordering problems and conditional statements. They replace a general feeling that an answer sounds right with a specific reason that it follows—or does not follow—from the clues.