Determine which of the lettered claims below is equivalent to the following: If the gun has a trigger lock, then it can be sold. (This can be easy to do if you symbolize the claims first and have some familiarity either with truth tables or with the Group II rules for derivations-the truth-functional equivalences.)
A)Only if the gun has a trigger lock can it be sold.
B)The gun has no trigger lock, but it can be sold anyway.
C)If the gun cannot be sold, then it has no trigger lock.
D)If the gun has no trigger lock, then it can be sold.

Question

Quizplus · Accepted Answer

The original statement is "If the gun has a trigger lock, then it can be sold," which can be symbolized as "T → S". The contrapositive of this statement, which is logically equivalent, is "If the gun cannot be sold, then it has no trigger lock," symbolized as "¬S → ¬T".

Determine Which of the Lettered Claims Below Is Equivalent to the Following