Some logic exercises

Here are a few exercises you guys can play with for practice. The assignment:

1. Identify the truth value of each proposition in the arguments below.
2. Identify whether each argument is valid or invalid.
3. Identify whether each argument is sound or unsound.

All marsupials are cute.
All little koalas are marsupials.
Therefore, all little koalas are cute.

All bubbles are poppable.
All dreams are like bubbles.
Therefore, all dreams are poppable.

If cleanliness is next to godliness, then mangoes are yummy.
Mangoes are yummy.
Therefore, cleanliness is next to godliness.

If cleanliness is next to godliness, then mangoes are yummy.
Cleanliness is next to godliness.
Therefore, mangoes are yummy.

If cleanliness is next to godliness, then mangoes are yummy.
Cleanliness is not next to godliness.
Therefore, mangoes are not yummy.

If cleanliness is next to godliness, then mangoes are yummy.
Mangoes are not yummy.
Therefore, cleanliness is next to godliness.

If cleanliness is next to godliness, then mangoes are yummy.
Mangoes are not yummy.
Therefore, cleanliness it not next to godliness.

All computers have keyboards.
All pianos have keyboards.
Therefore all pianos are computers.

We'll go over these on Monday. Hope you guys don't get a headache!