Consider this argument: "If we bought the movie tickets online, we saved a dollar per ticket. We did buy the tickets online. So we must have saved a dollar per ticket." Using a truth table to evaluate that argument for validity will produce a final column that ___________________.
A) has eight rows all of which are T
B) has eight rows some of which are T and some F
C) has four rows all of which are F
D) has four rows all of which are T
E) has two rows both of which are T

Question

Quizplus · Accepted Answer

The argument involves two statements: "If we bought the movie tickets online, we saved a dollar per ticket" and "We did buy the tickets online." These can be translated into two separate propositions, P and Q. P represents the statement "If we bought the movie tickets online, we saved a dollar per ticket," and Q represents the statement "We did buy the tickets online." Using a truth table with columns for P, Q, and "P implies Q," there will be four rows, all of which are T, in the final "P implies Q" column. Therefore, the argument is valid, and the best choice is D, which states that the truth table will have four rows all of which are T.

Consider This Argument: "If We Bought the Movie Tickets Online