7. a. A
B
A S B
B S A
(A S B) 4 (B S A)
T
T
T
T
T
T
F
F
T
F
F
T
T
F
F
F
F
T
T
T
Answers to Practice Problems
Note to student: Finish all parts of a practice problem before turning to the
answers.
C h a p t e r 1
1. False, false, false
2.
A
B
A ~ B
T
T
T
T
F
T
F
T
T
F
F
F
3.
A
B
A S B
T
T
T
T
F
F
F
T
T
F
F
T
4.
A
A′
T
F
F
T
5. a. Antecedent: The rain continues Consequent: The river will flood
b. Antecedent: The central switch goes down Consequent: Network failure
c. Antecedent: The avocados are ripe Consequent: They are dark and soft
d. Antecedent: A healthy cat Consequent: A good diet
6. Answer d. This is negation of A ` B, the same as the negation of “Peter is tall and thin.”
b. A
B
A′
B′ A ~ A′ B ` B′ (A ~ A′) S (B ` B′)
T
T
F
F
T
F
F
T
F
F
T
T
F
F
F
T
T
F
T
F
F
F
F
T
T
T
F
F
813