IBPS RRB Officer Prelims 10 Sep 2017 Paper

(i) All alternatives are choices →Universal Affirmative (A–type).
(ii) Some posts are mails→ ParticularAffirmative (I–type)
(iii) No letter is circular → UniversalNegative (E–type).
(iv) Some letters are not circulars→ Particular Negative (O–type).
Some planets are stars.
No star is a comet.
I + E ⇒ O-type of Conclusion“Some planets are not comets”.
All moons are stars.
No star is a comet.
A + E⇒ E-type of Conclusion“No moon is a comet”.
Venn diagrams of “Some planetsare stars” :


After combining venn diagramsII and IV, we get

Venn diagram VI contradictsConclusion I.
Venn diagrams of “Some planetsare not comets” :
It is clear from the above venndiagrams that Conclusion IIfollows.