ASSIGNMENT 1: (five points each)

A. Determine whether the following deductive arguments are valid or invalid.

1. Chicago is either in Illinois or Wisconsin. But it's not in Wisconsin. It follows that Chicago is in Illinois.

2. If the moon is made of green cheese, then there are mice on the moon. The moon is made of green cheese, therefore there are mice on the moon.

3. My birthday is six days after my sister's birthday. My birthday is on the 12th. Therefore, my sister's birthday is on the 18th.

4. Mark Thompson is a plagiarizer. Therefore, it follows that he has used other people's work without giving credit.

5. If a computer is made by IBM, then it comes with a warranty. Apple computers are not made by IBM. Therefore, Apple computers do not come with a warranty.

B. Determine whether the following inductive arguments are strong or weak.

1. The Nobel prize-winning biologist Herbert Ralls has stated that chlorinated hydrocarbons in our water supply constitute a major threat to the public health. Furthermore, no scientists disagree with him on this point. Accordingly, we conclude that the presence of these chemicals is indeed a threat.

2. Both Dorothy and Olivia have trouble seeing distant objects clearly. After purchasing a pair of prescription glasses, however, Dorothy reports that she can see perfectly. Therefore, if Olivia purchases a pair of glasses identical to Dorothy's, her vision should be as good as Dorothy's is now.

3. Two weeks after Pope John Paul II visited Los Angeles, the city suffered a severe earthquake. Therefore, if city officials would inform Pope John Paul that he is not welcome to return to LA, they would reduce the chances of another severe quake in the future.

4. The last twenty-two lottery tickets that Francis has purchased have been losers. Therefore, the next one he buys is virtually certain to be a winner.

5. Steve Howe, Alan Wiggins, and LaMarr Hoyt are baseball players and all have been involved with drugs. It must be the case that all baseball players use drugs.

ASSIGNMENT 2: (10 points each)

Determine whether the following arguments are inductive or deductive and correspondingly valid/invalid or strong/weak. Think carefully!

1. Most birds can fly and a penguin is a bird. So, penguins most probably can fly.

2. If the communists ever dominate Southeast Asia, then within five years they will eventually take power in all Asia. And, if they win Asia then within ten years they will take over the rest of the world. Thus, once the communists win S. E. Asia, they will soon dominate the world.

3. Either you will make an A in this course or you will make a B, C, D, E, or I. You did not make a B, C, D, E, or I. So, you must have made an A.

4. No Vietnam veterans should suffer from chronic health problems from exposure to Agent Orange because some authorities say that there is no necessary link between their diseases and their exposure to this toxin.

5. All birds have wings. A cat is a bird. Hence, a cat must necessarily have wings