Problem 4 - Entrance Test

Statements: 1. All birds are animals. 2. All animals are mammals. Conclusions: I. Some birds are mammals. II. All birds are mammals.

A. A. Only conclusion I follows.B. B. Only conclusion II follows.C. C. Either conclusion I or II follows.D. D. Neither conclusion I nor II follows.E. E. Both conclusions I and II follow.

Correct: E

Let's represent the statements: Statement 1: All birds are animals. (Birds circle is entirely inside Animals circle). Statement 2: All animals are mammals. (Animals circle is entirely inside Mammals circle). Combining the statements: Since 'All birds are animals' and 'All animals are mammals', it logically follows that 'All birds are mammals'. Now, let's analyze the conclusions: I. Some birds are mammals. If 'All A are B' is true, then 'Some A are B' must also be true. Since 'All birds are mammals' is true, 'Some birds are mammals' is also true. Thus, Conclusion I follows. II. All birds are mammals. This conclusion directly follows from the combination of the two statements. Thus, Conclusion II follows. Therefore, both conclusions I and II follow.