1. Evaluating truth tables
Unit 1
Methods/Logic

2. Is this valid or invalid?
P  Q P Q P Q P Q
P  Q T F
Both Premises are True on the Bottom Row and the Conclusion is True, as well. This argument is…….
VALID

3. IS THIS VALID OR INVALID?P Q Q
P  Q T F
P  Q Q P
Both Premises are True In the Second Row and the Conclusion is True, as well. This argument is…….

4. Is this valid or invalid?P Q R
P  Q
Q  R T F
P  Q Q  R P R
All three premises are true in rows one, three and four.
However, the conclusion in row four is false. What do you think this means?
Since there is at least one case which all the premises are true but the conclusion is false, this argument is…
INVALID

5. IS THIS VALID OR INVALID?
P  Q
P  R P Q R
P  Q
P  R T F
The premise is true in rows one and two where the conclusion is true as well. This argument is…
VALID

6. Sorry…This PowerPoint was brutal! (The next one is going to worse )
ube.com/watch?v=J r7bRw0NxQ4