Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusion(s) logically follow(s) from the statements.
Statements:
All cats are bills.
No snakes are bills.
All snakes are dolls.
Conclusions:
(I) Some dolls are not cats.
(II) No bills are dolls.
Only conclusion (I) follows.
This problem involves logical reasoning based on given statements and conclusions. We need to determine which conclusion(s) logically follow from the statements, assuming the statements are true.
Let's break down each statement and understand the relationship between the sets mentioned (Cats, Bills, Snakes, Dolls).
This means the set of 'cats' is entirely contained within the set of 'bills'. If something is a cat, it must also be a bill.
We can represent this as: Cats ⊆ Bills.
This means the set of 'snakes' and the set of 'bills' are completely separate; they have no members in common. If something is a snake, it cannot be a bill, and vice versa.
We can represent this as: Snakes ∩ Bills = ∅ (empty set).
This means the set of 'snakes' is entirely contained within the set of 'dolls'. If something is a snake, it must also be a doll.
We can represent this as: Snakes ⊆ Dolls.
Now, let's examine each conclusion based on the relationships established by the statements.
Let's combine the information:
Since all snakes are dolls (Statement 3) and no snakes are bills (Statement 2), we can infer that the snakes, which are a type of doll, are definitely not bills.
Furthermore, since all cats are bills (Statement 1), and we just established that snakes (which are dolls) are not bills, it follows that these snakes cannot be cats.
Therefore, there exists at least one group within the set of 'dolls' (namely, the snakes) that is not part of the set of 'cats'. This directly supports the conclusion that 'Some dolls are not cats'.
Conclusion (I) logically follows.
Let's consider the relationships again:
These statements tell us that the snakes (which are dolls) are separate from bills. However, they do not provide information about whether other members of the 'Dolls' set (those that are not snakes) might also be members of the 'Bills' set.
It is possible for an object to be both a bill and a doll, as long as it is not a snake. For example, imagine a doll that is also a bill, but this doll is neither a cat nor a snake. This scenario does not contradict any of the given statements.
Because we can conceive of a situation where a bill is also a doll (without violating the given statements), the conclusion 'No bills are dolls' cannot be definitively proven true.
Conclusion (II) does not necessarily follow.
Based on the analysis, only Conclusion (I) logically follows from the given statements.