Statements: All pens are books. All books are tables. Some tables are chairs. Conclusions: I. Some chairs are books.
II. All pens are tables. Which conclusion(s) logically follow(s)?

All pens ⊂ books ⊂ tables, so every pen is a table — II follows. 'Some tables are chairs' only guarantees an overlap of tables and chairs, which may lie outside the books region, so 'Some chairs are books' is not guaranteed — I does not follow.