Determine whether the argument in the problem below is valid or invalid. If valid, name the type of reasoning and if invalid, determine the error in reasoning. Assume that if a number is odd, then it is not even.

If a³ is even, then a must be even.
A is odd.
Therefore, a³ is odd.

Question

Quizplus · Accepted Answer

The argument is valid and uses indirect reasoning (contrapositive). If $ a^3 $ is even, then $ a $ must be even. The contrapositive is: if $ a $ is odd, then $ a^3 $ is odd, which is the conclusion.

Determine Whether the Argument in the Problem Below Is Valid