1. At least one school is a tertiary institution.

All universities are tertiary institutions.

Therefore, at least one school is not a university.

Provide answers for questions 'a' to 'l' below from the passage immediately above.

1. If the statement "some schools are not tertiary institutions" is true, what is the immediate inference of this 'O' statement? (2 marks)

1. What is the obverse of the A-Statement above? (1 mark)

1. What is the converse of 'some schools are not tertiary institutions'? (1 mark)

1. Is the converse of the statement in 'C' above true? (1 mark)

1. Use Venn diagrams to prove that the converse of 'I' statements is always true. (4 marks)

1. Rewrite the argument above as a standard-form categorical syllogism (3 marks)

1. Identify its mood and figure: (2 marks)

1. Test its validity using a Venn diagram. (5 marks)

1. What can be said about the validity of the argument above? (1 mark)

1. Why would you or would you not use a truth table to test the argument above? (1 mark)

1. Use your own substitution instances to demonstrate how contraries work. (2 marks)

1. Use some substitution instances to show how sub-contraries work. ( 2 marks)