11
Q:

Some tapes are discs. Some discs are cassettes. Some cassettes are songs

Conclusions:

1. Some songs are discs

2. Some cassettes are tapes

3. Some songs are tapes

4. No song is a disc

A) Only either 1 or 4 follows B) Only either 2 or 4 follows
C) Only 3 and 4 follow D) Only 3 and either 2 or 4 follows

Answer:   A) Only either 1 or 4 follows



Explanation:

Since each combiantion of premise contain 2 particular premises, no definite conclusion can be drawn. However, 1 and 4 involve the extreme terms of 2nd and 3rd premises and form a complementary pair. Thus either 1 or 4 follows.