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QUIZ 1.3

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QUIZ 1.3:
Valid and Invalid Arguments

QUIZ 1.3:
Valid and Invalid Arguments

QUIZ 1.3 Valid and Invalid Arguments

Instruction: Read each item carefully and select the best answers. Hit the submit button once you are done.


1
For an argument to be invalid means that there is an argument of the same form whose premises _____ and whose conclusion _____.


2
An inverse error is also known as the fallacy of:


3
Determine the validity of the argument form below.
If this number is larger than 2, then its square is larger than 4.
This number is not larger than 2.
Therefore, the square of this number is not larger than 4.


4
"Ana knows numerical analysis and Ana knows graph algorithms. Therefore, Ana knows graph algorithms."
The argument form above is valid by what rule of inference?


5
Determine whether the argument form below is valid.
$$p$$
$$p\rightarrow q$$
$$\sim q\vee r$$
Therefore: $$r$$


6
Given the following information about a computer program, find the mistake in the program.
  1. There is an undeclared variable or there is a syntax error in the first five lines.
  2. If there is a syntax error in the first five lines, then there is a missing semicolon or a variable name is misspelled.
  3. There is not a missing semicolon.
  4. There is not a misspelled variable name.


7
Construct a truth table showing the argument form:
$$p \wedge q \rightarrow \sim r$$
$$p \vee \sim q$$
$$\sim q \rightarrow p$$
Therefore: $$\sim r$$
What fraction of the critical rows are evaluated as FALSE?


8
Read the following clues and apply the rules of inference in figuring out the location of the treasure.
  1. If this house is next to a lake, then the treasure is not in the kitchen.
  2. If the tree in the front yard is an elm, then the treasure is in the kitchen.
  3. This house is next to a lake.
  4. The tree in the front yard is an elm or the treasure is buried under the flagpole.
  5. If the tree in the back yard is an oak, then the treasure is in the garage.
Therefore, the treasure is:


9
Consider the argument form below.
  1. $$x - 3 = 0$$ or $$x + 2 = 0$$.
  2. $$x$$ is nonnegative.
  3. Therefore, $$x = 3$$.
What rule of inference makes the argument form above valid?


10
If you can show that the supposition that statement p is false leads logically to a _____, then you can conclude that p is true.