Math 114

 

Logic Unit

 

Test Review

 

1)      Fill in the blank

 

Connector

Symbol

Or

And

If-then

Negation

~

 

Negation each statement

 

2)      All cats are friendly

 

Answer: Some cats are not friendly

 

3)      John likes ice cream.

 

Answer: John does not like ice cream

 

Using the symbolic representations

 

p: The cat is friendly

q: The cat is playful

 

Express the following compound statements in symbolic form.

 

a)      The cat is friendly and the cat is playful

 

b)      Either the cat is playful or the cat isn’t friendly

     

     

c)      If the cat is playful, then the cat is friendly.

 

     

 

 

 

 

 

 

Complete the each true table.

 

4)

 

P

Q

T

T

T

T

F

T

F

T

T

F

F

F

5)

 

P

Q

T

T

T

T

F

F

F

T

F

F

F

F

 

6)

 

p

Q

T

T

T

T

F

F

F

T

T

F

F

T


Complete each truth table

 

7)

 

p

q

~p

T

T

T

F

F

T

F

T

F

F

F

T

T

T

T

F

F

F

T

T

 

8)

 

p

q

 

T

T

T

T

T

F

F

T

F

T

F

T

F

F

F

T

 

 

Validity

 

1)      Write the argument in symbolic form, then determine if the argument is valid

      p: you exercise regularly

            q: you are healthy

 

If you are healthy, you exercise regularly.

You don’t exercise regularly

Therefore, you are not healthy.

 

If you are healthy, you exercise regularly.

You don’t exercise regularly

Therefore, you are not healthy.

 

: hypothesis

: conclusion

 

       

p

q

T

T

T

F

F

F

T

T

F

T

F

F

T

T

F

T

F

T

F

F

T

F

F

T

T

T

T

T

 

The argument is valid

 

Determine if the argument uses inductive reasoning or deductive reasoning

 

1)      Math 114 is a math course

Math courses are fun

Math 114 is fun

 

Deductive reasoning

 

2)      John had a chemistry quiz on Monday.

John had a chemistry quiz on Wednesday

Therefore, John will have a quiz on Friday

 

Inductive reasoning

 

 

 

 

 

 

Solutions to the Test 1 Review

 

Test 1 Review (Math 114) Radford University

 

Solutions

 

I)                   Reasoning and statements

 

1)      Do the following arguments use deductive reasoning or inductive reasoning

 

a)      Stan noticed that a plane flew over his house at 5:00 PM Monday

Stan noticed that a plane flew over his house at 5:00 PM Tuesday

Stan noticed that a plane flew over his house at 5:00 PM Wednesday

Therefore, Stan concludes that a plane will fly over his house everyday at 5:00 PM

 

(Inductive reasoning)

 

b)      All mountain ranges are scenic.

The Blue Ridge Mountains are a mountain range

Therefore, the Blue Ridge Mountains are scenic.

 

(Deductive reasoning)

 

2)      Negate the following statements.

 

a)      All trees have green leaves

 

Negation: Some trees do not have green leaves

 

b)      Some food at Greasy Nicks taste good.

 

      Negation: All food at Greasy Nicks does not taste good.

 

c)      John loves to play football

 

       Negation:  John does not love to play football

 

 

 

 

 

 

 

 

II)                Complete a truth table for each statement

 

      3)

 

Solution:     

p

q

~q

T

T

F

T

T

F

T

T

F

T

F

F

F

F

T

T

 

 

      4)

 

      Solution:    

 

p

q

~p

T

T

F

T

F

T

F

F

F

F

F

T

T

T

T

F

F

T

T

T

 

 

 

      5)

 

      Solution:    

 

p

q

~q

T

T

F

T

T

T

F

T

T

F

F

T

F

F

F

F

F

T

T

F

 

 

III)             Use De Morgan’s Law to negate each statement

 

       6)

       

Negation:

 

       7)

 

Negation:

IV)             Determine if the argument is valid or invalid.

 

8)      If John studies for his math test, he will pass the math test.  

John did not pass his math test

Therefore, john did not study for his math test

 

Argument:

 

p

q

~p

~q

T

T

F

F

T

F

T

T

F

F

T

F

F

T

F

T

T

F

T

F

T

F

F

T

T

T

T

T

                               

Invalid argument

 

8)      If you work hard, then you will go far in life 

You work hard  

Therefore, you will go far in life.  

 

             Argument: 

           

    

p

q

T

T

T

T

T

T

F

F

F

T

F

T

T

F

T

F

F

T

F

T

 

This argument is a tautology, so the argument is valid