Question

Given the following statements, which answer uses deductive reasoning to draw the conclusion?

Answer 1

Determine whether the stated conclusion is valid based on the given information. If not, write invalid. Explain your reasoning.
3. Given: If a number is divisible by 4, then the number is divisible by 2. 12 is divisible by four.
Conclusion: 12 is divisible by 2.
SOLUTION:
If p → q is a true statement and p is true, then q. Here, a number divisible 4 is divisible by 2 also and 12 is divisible by 4. So, 12 is divisible by 2 is a valid statement by the Law of Detachment.
ANSWER:
valid; Law of Detachment
4. Given: If Elan stays up late, he will be tired the next day. Elan is tired.
Conclusion: Elan stayed up late.
SOLUTION:
If p is true, then q is true, but q being true does not necessarily mean that p is true. Elan could be tired because he worked out. So, the statement is invalid.
ANSWER:
Invalid; Elan could be tired because he worked out.
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