Determine the truth value of the statement ~q <-> [ ~r /\ (p \/ q)] when p is false, q is true, and r is true. Substitute F for p, T for q, and T for r. You need these truth tables: ~T <=> F ~F <=> T T \/ T <=> T T \/ F <=> T F \/ T <=> T F \/ F <=> F T /\ T <=> T T /\ F <=> F F /\ T <=> F F /\ F <=> F T <-> T <=> T T <-> F <=> F F <-> T <=> F F <-> F <=> T Substitute F for p, T for q, and T for r. ~q <-> [~r /\ (p \/ q)] ~T <-> [~T /\ (F \/ T)] Replace both ~T's by F F <-> [F /\ (F \/ T)] Replace (F \/ T) by T F <-> [F /\ T] Replace [F /\ T] by F F <-> F Replace that by T Edwin