In each of the following questions, there are three statements followed by…

A particular affirmative statement of the form “Some A are B” can always be CONVERTED to “Some B are A” — a valid immediate inference drawn from that one statement alone. In contrast, two particular statements that share a common middle term, “Some A are B” and “Some B are C”, can NEVER be validly combined into “Some A are C”: this is the fallacy of the undistributed middle, since the word “some” does not distribute the middle term B, so the two premises may be referring to different, non-overlapping parts of B.

1. Envelopes–seals: Statement 1 (“Some envelopes are gums”) and Statement 2 (“Some gums are seals”) share the middle term “gums” — two particular premises, so linking them into “Some envelopes are seals” is the undistributed-middle fallacy; it does not follow.

2. Gums–adhesives: Statement 2 (“Some gums are seals”) and Statement 3 (“Some seals are adhesives”) share the middle term “seals” — again two particular premises, so “Some gums are adhesives” is the same fallacy; it does not follow.

3. Adhesives–seals: “Some adhesives are seals” is simply the CONVERSE of Statement 3 (“Some seals are adhesives”) — a valid immediate inference from that single statement, with no combination needed. It necessarily follows.

4. Adhesives–gums: this would need Statement 2 and Statement 3 chained through “seals” in the reverse direction — the same undistributed-middle fallacy as the gums–adhesives case; it does not follow.

Cross-check with a concrete model that satisfies all three statements: Envelopes = {1, 2}, Gums = {2, 3, 4}, Seals = {4, 5, 6}, Adhesives = {6, 7}. Every statement holds (2 is a shared envelope/gum, 4 is a shared gum/seal, 6 is a shared seal/adhesive), yet envelopes–seals, gums–adhesives and adhesives–gums share no common member here — confirming those three conclusions are not guaranteed. Adhesives–seals still holds (6), as it must in every model, since it is a direct conversion and not a chained inference.

So exactly one conclusion follows: “Some adhesives are seals” — matching Only (3).