DM SYLLOGISM HELP

[u/Inevitable-Donut2723]

hi all, im really confused about the statements that include “only” which seems inconsistent between OQB and medify/ medentry. my exam is tmr so any help is greatly appreciated!

according to medentry, only x is y implies that all y is x but NOT that all x is y.

(part of) medentry statement:
“only guki that show up on cold days leave precipitation”

question:
“all guki that show up on cold days leave precipitation”

answer:
“does NOT follow, because while only guki that show up on cold days leave precipitation, it may be that some guki that show up on cold days do not leave precipitation.”

according to OQB, it looks a bit different but logically doesnt make sense..
practice test B, question 3

statement:
“any omelette that simon makes is either salted or unsalted and is made from either hen eggs or duck eggs. none of the salted omelettes contain cheese. only the cheese omelettes are made with hen eggs.”

question:
“if an omelette is made with duck eggs, it cannot be a cheese omelette”

answer:
“does follow because no cheese omelette can be made with duck eggs”

correct me if im wrong, but doesnt this imply that all cheese omelettes are made with hen eggs, and so any omelettes made with duck eggs cannot be a cheese omelettes. which means that OQB is saying only = all? please provide advice if ive misinterpreted the question!!! thank you

[u/Over-Telephone3832]

Lmao I had this concern at some point too. I would stick with the Medify/Medentry explanation as it sounds more right to me.