Exercise: validity and soundness

Is it possible to have arguments of the following kinds?

If so, provide an example. If not, explain why. It is particularly important to note the highlighted cases.

	True conclusion true premises	True conclusion false premises	False conclusion true premises	False conclusion false premises
Valid & sound arguments	[Show answer] Yes. "Cows are mammals. Mammals are animals. So cows are animals."	[Show answer] No. If the premises are false, the argument is not sound.	[Show answer] No. If the premises are true and the argument is valid, the conclusion must also be true.	[Show answer] No. If the premises are false, the argument is not sound.
Valid & unsound arguments	[Show answer] No. If the premises are true and the argument is valid, the argument is sound.	[Show answer] Yes. "Cows are insects. Insects are mammals. So cows are mammals."	[Show answer] No. If the premises are true and the argument is valid, the conclusion must also be true.	[Show answer] Yes. "Cows are insects. Insects are viruses. So cows are viruses."
Invalid & sound arguments	[Show answer] No. By definition a sound argument has to be valid.	[Show answer] No. By definition a sound argument has to be valid.	[Show answer] No. By definition a sound argument has to be valid.	[Show answer] No. By definition a sound argument has to be valid.
Invalid and unsound arguments	[Show answer] Yes. "Cows are mammals. So the sun is larger than the moon."	[Show answer] Yes. "Cows are insects. So the sun is larger than the moon."	[Show answer] Yes. "Cows are mammals. So the moon is larger than the sun."	[Show answer] Yes. "Cows are insects. So the moon is larger than the sun."