1. No barracuda are pets. I

ANS-12 Answers to Selected Exercises 4. t a w ˜t t a ˜t a a v w ˜t a C 1. T T T F T F T F

2. T

T F F T F T F 3. T F T F F T T F

4. T

F F F F T F F 5. F T T T F T T T

6. F

T F T F T T T 7. F F T T F T T F

8. F

F F T F T F F Invalid. V. 1. d v r ˜ r ... d d r d v r ˜r d C T T T F T T F T T T F T T F F F F F T F Valid. 4. s v a ˜ s a a ... s s a s a s v a ˜s a a s C T T T T F T T T F F T T F T F T F T T T F F F F F T F F Invalid. E X E R C I S E 10 .6

I. 1. F

4. T 7. F

10. T

III. 1.

b → e 4. h → f 7. ˜ c → ˜ e 10. s → g → ˜ s → p

IV. 1.

p q p → q ˜p ˜q C 1. T T T F F 2. T F F F T 3. F T T T F 4. F F T T T Invalid. b m t ˜m ˜t m b b ˜t ˜m b ˜m ˜t C 1. T T T F F T F F F

2. T T F F

T T T F F 3. T F T T F F F T F 4. T F F T T F T T T

5. F T T F

F F F T F 6. F T F F T F F T F

7. F F T T F

F F T F

8. F F F T

T F F T T Valid.

V. 1.

f t ˜ s ... ˜ f s f t s f s f t ˜s ˜ f sC 1. T T T T T F F 2. T T F F T T T 3. T F T T F F F 4. T F F F F T T 5. F T T F F F T 6. F T F F F T T 7. F F T F F F T 8. F F F F F T T Valid. 4. s ˜ e ˜ e t ... s t s e t ˜e e t s ˜e ˜e t s t C 1. T T T F T F F T

2. T

T F F F F T F 3. T F T T F T T T

4. T

F F T F T T F 5. F T T F T F F F

6. F

T F F F F T F 7. F F T T F F T F

8. F

F F T F F T F Invalid. E X E R C I S E 10 .5 I. III. 1. T 1. d v r 4. T 4. w v d 7. T 7. p v f 10. F 10. ˜ t v a w

IV. 1.

p q p v q ˜p q C T T T F T T F T F F F T T T T F F F T F Valid. Answers to Selected Exercises ANS-13 4. Is the sample large enough? Possibly, depending on the size of the faculty. Is the sample representa- tive? No, they are all from one department. Other departments may tenure far fewer applicants for tenure. E X E R C I S E 11.4

I. 1. c Strong and reliable.

4. c Strong and reliable. 7. c Strong and reliable. 10. c Strong and reliable. E X E R C I S E 11.6 1. 2: The skills involved are very different. 4. 5: There are big differences between a small family budget and a large city budget. 7. 7: The argument does not claim very much, and considering Jordan’s athletic ability, love for the game, and practice, it isn’t unreasonable to claim he could learn to play tennis fairly well. 10. 3: The conclusion is too strong in claiming he must be “ just like” the character. There are a couple of important similarities but not enough to fully sup- port the conclusion. E X E R C I S E 11.8

I. 1. Strong.

4. Weak.

II. 1. a. Strengthen.

b. Strengthen. c. Weaken. d. Strengthen. 4. a. Strengthen. b. Weaken. c. Weaken. d. Strengthen. E X E R C I S E 11.10

I. 1. Bad evidence.

4. Good evidence. 7. Good evidence. 10. Good evidence. II. 1. What else did he eat? Did anyone else become sick from eating it? 4. The percentage of women with breast implants who have connective tissue disease; the percentage of 4. p q r ˜p ˜q p → q ˜q v r ˜p r C

1. T

T T F F T T F 2. T T F F F T F F

3. T

F T F T F T F 4. T F F F T F T F

5. F

T T T F T T T 6. F T F T F T F F

7. F

F T T T T T T 8. F F F T T T T F Invalid.

V. 1.

b → e ˜ e ... ˜ b b e b → e ˜e ˜ b C 1. T T T F F 2. T F F T F 3. F T T F T 4. F F T T T Valid. 4. g → s ... ˜ g → ˜ s g s ˜g ˜s g → s ˜g → ˜s C

1. T

T F F T T 2. T F F T F T

3. F

T T F T F 4. F F T T T T Invalid. C H APT ER 11 E X E R C I S E 11.1 1. Strong. 4. Strong. 7. Strong. 10. Weak. E X E R C I S E 11.2 I. 1. Strong. Is the sample large enough? Yes. Is the