Here are my answers to Stanford Introduction To Logic: 3.5.
In each of the following cases, determine whether the given individual sentence is consistent with the given set of sentences.
a. {p ∨ q, p ∨ ¬q, ¬p ∨ q} and (¬p ∨ ¬q)
Using a truth table:
p q p ∨ q p ∨ ¬q ¬p ∨ q ¬p ∨ ¬q
T T T T T F F T T F T T T F T T F T F F F T T T
So no, the sentence isn't consistent.
b. {p ⇒ r, q ⇒ r, p ∨ q} and r
p q r p ⇒ r q ⇒ r p ∨ q r
T T T T T T T F T T T T T T T F T T T T T F F T T T F T T T F F F T F F T F T F T F T F F F T T F F F F T T F F
The first interpretation satisfies the formula, so yes it is consistent
c. {p ⇒ r, q ⇒ r, p ∨ q} and ¬r
p q r p ⇒ r q ⇒ r p ∨ q ¬r
T T T T T T F F T T T T T F T F T T T T F F F T T T F F T T F F F T T F T F T F T T T F F F T T T F F F T T F T
The formula is unsatisfiable, so not consistent.
d. {p ⇒ q ∨ r, q ⇒ r} and p ∧ q
p q r p ⇒ q ∨ r q ⇒ r p ∧ q
T T T T T T F T T T T F T F T T T F F F T T T F T T F T F T F T F T T F T F F F F F F F F T T F
The formula is satisfiable, so consistent.
e. {p ⇒ q ∨ r, q ⇒ r} and q ∧ r
p q r p ⇒ q ∨ r q ⇒ r p ∧ q
T T T T T T F T T T T F T F T T T F F F T T T F T T F T F T F T F T T F T F F F F F F F F T T F
The formula is satisfiable, so consistent.