So... who's good at BASIC LOGIC??? MaGilicuti needs your help once again

[MaGilicuti]

online test, i haven't read the book and i am paying for it...

anyone know this shit? i have 10 multipe choice questions here i could just bullshit but would rather not. um, is there a message board somewhere for ppl that need help with their hw like?


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Question 1 (10 points)
A valid argument may have false premises
1. True
2. False

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Question 2 (10 points)
A sound argument may have false premises.
1. True
2. False

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Question 3 (10 points)
A counterexample is a row on a truth table on which the premises are false and the conclusion is true.
1. True
2. False

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Question 4 (10 points)
An invalid argument may have true premises.
1. True
2. False

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Question 5 (10 points)
A sound argument may still be invalid.
1. True
2. False

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Question 6 (10 points)
If X is a logical truth and Y is a contradiction, then the argument ' X therefore Y ' is
1. valid
2. Invalid
3. Can't tell

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Question 7 (10 points)
If X is a contradiction and Y is a logical truth, then the argument ' X therefore Y ' is
1. Valid
2. Invalid
3. Can't tell

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Question 8 (10 points)
If X is contingent and Y is a contradiction, then the argument ' X therefore Y ' is:
1. Valid
2. Invalid
3. Can't tell

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Question 9 (10 points)
If X is a logical truth and Y is contingent, then the argument ' X therefore Y ' is:
1. Valid
2. Invalid
3. Can't tell

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Question 10 (10 points)
If X is contingent and Y is contingent, then the argument ' X therefore Y ' is:
1. Valid
2. Invalid
3. Can't tell

 

[OMEGA]

question 1 A

question 2 B IMO

 

[Kahn]

#'s 1-5, True but needs to be clearer on premises shit
#6 2
#7 1
#'s 8-10, 3

 

[MaGilicuti]

kahn u serious?

 

[Warik]

1) True. Validity of an argument depends only on whether or not the conclusion necessarily follows from the premises if they are assumed to be true.

2) False. A false premise automatically makes the argument unsound regardless of its validity.

3) True (not certain).

Premise: Al Gore is smarter than Bill Clinton.
Conclusion: Bill Clinton is an idiot.

The conclusion is true, but the premise is false.

4) True.

Premise: My dick is big.
Premise: Your dick is small.
Conclusion: Your dick is bigger than mine.

Invalid argument, true premises. (bwahahah )

5) False (not certain) I believe validity is a prerequisite of soundness.

6) I think this is the old T, therefore F statement. I'll have to say invalid.

7) Hot damn... it is the old T, therefore F statement. Valid

8-10) Can't tell... at least I can't. Never heard my teacher say "contingent."

How'd I do? =)

-Warik

 

[MaGilicuti]

i went with warik's answers, they made a lot of sense with the examples. thank you warik. if you need anything just pm me and i will try my best to get it, seriously. will post results in a few

 

[MaGilicuti]

1 (10 points)
A valid argument may have false premises
100.0% 1. True
0.0% 2. False


Score: 10 / 10



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2 (10 points)
A sound argument may have false premises.
0.0% 1. True
100.0% 2. False


Score: 10 / 10



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3 (10 points)
A counterexample is a row on a truth table on which the premises are false and the conclusion is true.
0.0% 1. True
100.0% 2. False


Score: 10 / 10



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4 (10 points)
An invalid argument may have true premises.
100.0% 1. True
0.0% 2. False


Score: 10 / 10



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5 (10 points)
A sound argument may still be invalid.
0.0% 1. True
100.0% 2. False


Score: 10 / 10



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6 (10 points)
If X is a logical truth and Y is a contradiction, then the argument ' X therefore Y ' is
0.0% 1. valid
100.0% 2. Invalid
0.0% 3. Can't tell


Score: 10 / 10



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7 (10 points)
If X is a contradiction and Y is a logical truth, then the argument ' X therefore Y ' is
100.0% 1. Valid
0.0% 2. Invalid
0.0% 3. Can't tell


Score: 10 / 10



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8 (10 points)
If X is contingent and Y is a contradiction, then the argument ' X therefore Y ' is:
0.0% 1. Valid
100.0% 2. Invalid
0.0% 3. Can't tell
No. Remember 'contingent' means at least one case in which it is true and at least one case in which it is false. Since Y is always false, there will be at least one line where X is true and Y is false. But this is a counterexample.


Score: 0 / 10



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9 (10 points)
If X is a logical truth and Y is contingent, then the argument ' X therefore Y ' is:
0.0% 1. Valid
100.0% 2. Invalid
0.0% 3. Can't tell
No. X is always true. Since Y is contingent, there is at least one case in which Y is false. But this means there is at least one counterexample.


Score: 0 / 10



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10 (10 points)
If X is contingent and Y is contingent, then the argument ' X therefore Y ' is:
0.0% 1. Valid
0.0% 2. Invalid
100.0% 3. Can't tell


Score: 10 / 10

 

[Warik]

If you know any scary, unsavory individuals who could scare my technical writing teacher into not giving me a BS grade on my final paper due to his bias against me, it would be most appreciated.

j/k. I'll add you to my list of "people who have agreed to owe me a favor" list.

*pulls out blank sheet of paper and writes MaGilicuti's name on it *

lemme know those results... I was pretty sure of everything up until #8+.

-Warik

 

[Warik]

Hah! 100% on the non-contingent ones. *flex* I thought "contingent" meant "sometimes true sometimes false," but wasn't sure.

Damn I'm good. *flex* Any more?

-Warik

 

[MaGilicuti]

Warik was right on all his shit. Thanks man. wanna take a look at this one?

i have to do 2 more test in about 30 minutes before they are cut off. just fucking realized it now and i've been sitting here all day doing shit


Question 1 (10 points)
What is the antecedent of the condition ' (A & B) --> C' ?

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Question 2 (10 points)
What is the consequent of the conditional " A -->( B --> C) " ?

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Question 3 (10 points)
Write a conditional that is logically equivalent to the sentence " ~(A & ~B).

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Question 4 (10 points)
Write a conditional that is logically equivalent to ' A --> B ' in which ' ~B ' is the antecedent.

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Question 5 (10 points)
Write a sentence ' using the double arrow <--> that is logically equivalent to ' (A --> ~B) & (~B --> A).

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Question 6 (10 points)
If ' X ' and ' Y ' are logically equivalent, then the sentence X <--> Y is a:
1. Logical Truth
2. Contingent
3. Contradiction

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Question 7 (10 points)
Determine whether the argument A --> (B & C) A Therefore, C is valid or invalid. If invalid, give a row where a counterexample appears.
1. Valid
2. Invalid

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Question 8 (10 points)
Determine whether the argument A --> (B --> C) B --> C Therefore, A is valid or invalid. If invalid, give a row where a counterexample appears.
1. Valid
2. Invalid


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Question 9 (10 points)
Translate the following sentence into (SL): If Ann is home, then if Bob is too, so is Carol.


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Question 10 (10 points)
Translate the following sentence into (SL): Carol is home, if Ann and Bob are.

 

[MaGilicuti]

this test i really don't fucking understand...

WARIK!!! HELP!!!!

 

[Warik]

1) (A & B)

2) (B --> C)

3) ~A OR B

4) ~B --> ~A

5) (A --> ~B) & (~B --> A) <-----> (B --> ~A) & (~A --> B)

6) Logical Truth

7) Valid (Question seems vague. I think, not absolutely certain).

8) Too many -->'s... I really don't want to do this one. Sorry.

9) A = Ann is home
B = Bob is home
C = Carol is home

A ---> (B & C)

10) C = Carol is home
A = Ann is home
B = Bob is home

(B & C) ---> A

How'd I do? =)

-Warik

 

[MaGilicuti]

i love you man . i didn't even bother looking those up, i just put those in word for word this time.

you want a free shirt atleast? i owe you

 

[Warik]

i love you man . i didn't even bother looking those up, i just put those in word for word this time.

you want a free shirt atleast? i owe you

That would be cool, but I'm a wussy natty, remember? bwahaha.

Got another test? How'd, uh... "we" do on this one?

-Warik

 

[MaGilicuti]

this is actually a test this time, not a quiz. hopefully he'll still accept it since its due in 2 minutes...

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Question 1 (5 points)
If X and Y are logically equivalent, then 'X therefore Y' is
1. valid
2. invalid
3. Can't tell.

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Question 2 (5 points)
Write a sentence logicically equivalent to ' ~( ~A v B) ' and give the rule that justifies it.


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Question 3 (5 points)
Which area(s) will be shaded on the Venn diagram for ' ~A v B ' ?


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Question 4 (5 points)
Which area(s) of a Venn diagram will be shaded for the sentence ~(A & B) ?


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Question 5 (5 points)
According to DeMorgan's laws, ~(X v ~Y) is logically equivalent to a
1. conjunction
2. disjunction
3. negation

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Question 6 (5 points)
According to the laws of distribution, the sentence ~X & (Y v Z) is logically equivalent to a
1. conjunction
2. disjunction
3. negation

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Question 7 (5 points)
Show that the sentence ' B v ~~A ' is logically equivalent to ' A v B'
1) ~~B v A
2)
3)

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Question 8 (5 points)
Show that ' (A v B) v B ' is equivalent to ' A v B '.
1) (A v B) v B
2)
3)


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Question 9 (5 points)
Show that ~(~A & B) is logically equivalent to ' A v ~B'.
1) ~(~A & B)
2)
3)



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Question 10 (5 points)
Show that A v ~B is logically equivalent to ~( ~A & B)
1) A v ~B
2)
3)


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Question 11 (5 points)
If ' A ' is contingent, the sentence ' A v ( B & ~B) ' is a:
1. Logical truth
2. Contradiction
3. Contingent


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Question 12 (5 points)
The sentence ' ( A & ~A) & B ' is a:
1. Logical truth
2. Contingent
3. Contradiction


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Question 13 (5 points)
All sound arguments are valid.
1. True
2. False


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Question 14 (5 points)
An invalid argument must have at least one false premise.
1. True
2. False

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Question 15 (5 points)
An invalid argument can have more than one counterexample
1. True
2. False

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Question 16 (5 points)
If X is a contradiction, then the argument 'X therefore Y' is valid.
1. True
2. False

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Question 17 (5 points)
If X is contingent and Y is a contradiction, then the argument 'X therefore Y' is:
1. Valid
2. Invalid

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Question 18 (5 points)
If X and Y are logically equivalent, then the argument ' X there fore Y' is:
1. Valid
2. Invalid


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Question 19 (5 points)
Determine on the basis of the truth table for ~A v B, A v C, ~B // C whether it is valid or invalid. If invalid, give the counterexample.
1. valid
2. invalid


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Question 20 (5 points)
Determine using a truth table whether the argument A v B, B v C, A // C is valid or invalid. If invalid, give the counterexample.
1. Valid
2. Invalid


Warik, i'll send you as many shirts as you want.

 

[MaGilicuti]

i do'nt know how "we" did on that last one yet. since most of it was open ended i think the teacher has to actually look at it rather then the computer just correcting it. i am confident "we" did alright though

 

[Warik]

Good God... 20 questions? This will require extreme measures.

BY THE POWER OF GRAYSKULL!!!

I HAVE THE POWER!!!!!!!

1) Valid.

2) A /\ ~B - DeMorgan's Law

3) B (including the intersection of A and b), and everything outside of A.

4) The entire diagram EXCEPT the area where A and B overlap.

5) Conjunction

6) Conjunction (I think)

7)
1. ~~B v A
2. B v A
3. A v B

8)
1. (A v B) v B
2. A v (B v B)
3. A v B

9)
1. ~(~A & B)
2. A v ~B - DeMorgan's law

10)
1. A v ~B
2. ~(~A & B) - DeMorgan's law

11) Logical Truth

12) Contradiction

13) True

14) False

15) True

16) True

17) Invalid

18) Valid

19 & 20) The wording of these questions suck and I do not understand them. Say valid in hopes that at least one is valid.

-Warik

 

[MaGilicuti]

if you really want the shirts just email me at [email protected]. i have no problem hooking u up. gonna post the results as soon as i get them.

warik, um.. you wanna check out one more?

 

[Warik]

warik, um.. you wanna check out one more?

Not really, but go ahead and post it. If it's ez I'll give it a shot before bed.

-Warik

 

[MaGilicuti]

Warik, seriously email for the shirt, i'll give u as many shirts as you want on top of whatever favor u'll need. that is if you want the shirt. but here's the last test


Question 1 (10 points)
Explain as best as possible in your own words what a 'valid inference' is. Give a ' real life ' example.


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Question 2 (10 points)
Give the full name of the valid rule of inference that allows one to safely infer Y from X --> Y and X.


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Question 3 (10 points)
Give the full name for the valid rule of inference that allows one to safely infer the truth of Y from the truth of X v Y and ~X.


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Question 4 (10 points)
Explain why it is permissible to infer ' X v anything you like ' from the truth of X.


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Question 5 (10 points)
Given the truth of X v Y, why can't you safely infer the truth of X without additional information. Refer to the 'truth conditions' for disjunction in your answer.



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Question 6 (10 points)
Given the truth of X --> Y and Y why can't we safely infer that X is true? Once again, think about the truth conditions for ' --> '.



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Question 7 (10 points)
Please derive B v C from the following premises: A --> B A
1) A --> B Premise
2) A Premise
3)
4)

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Question 8 (10 points)
Please derive C from the premises: A --> ( B v C) A ~B
1) A --> ( B v C) P
2) A P
3) ~B P
4)
5)


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Question 9 (10 points)
Please derive C from the premises: A --> ( B --> C) A B
1) A --> ( B --> C) Premise
2) A Premise
3) B Premise
4)
5)


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Question 10 (10 points)
Please derive the conclusion C from the premises: A v ~B B v C ~A
1) A v ~B Premise
2) B v C Premise
3) ~A Premise
4)
5)

 

[Warik]

eek. My teacher didn't go into inference when we covered logic. Sorry dude. =( Let me know how "we" did on the other tests/quizzes. =)

Shirt? I'll think about it. I hate accepting things in exchange for giving help that I would never ask anything in return for... but you seem insistent. =)

Hope you get a good grade.

-Warik

 

[MaGilicuti]

i'd feel bad if i didn't send you the shirt alteast, email me if you want it. thanks for your help man, i would have been DEAD in this class without you, totally forgot about it till now