LOGIC TEST

[Thike Salvmu]

How biased is your reasoning?

What did you score out of 30? (Tests 1 & 2)

 

http://www.think-logically.co.uk/lt.htm

 

 

[Ahuvah]

Thank goodness our logic is based on reasoning from the scriptures not the so called logic of the world - i scored nothing ... my thinking must not be logic.

[Cool Cat]

Test 1 :- 13

Test 2 :- 14

[ChocoBro]

I only did the first test and scored all correct except the last two question. Don't know why I suddenly switched from deductive logic to inductive logic.. guess I got bored ^^

[ChrisC]

80% on both.

[carlos]

I obtained 87%. But I disagree with the answers in the test in the two cases where they differ from mine.

 

Well, actually I don't completely disagree with the first one. The fact that Mary was in the crime scene, touched the fatal weapon and got her clothes dirty with blood doesn't prove in itselft that Mary committed the crime. But since there is evidence that no one else entered the crime scene, there is simply no other rational explanation. So even if the reasoning is inductive, I think it's still perfectly valid from a logical viewpoint.

 

In the other case, I think the test is playing games with words. If water is defined as "a molecule composed of two hydrogen atoms and one oxygen atom", then anything with a different composition is not water, no matter if it looks like water or has many or all of water's properties. That logic is faulty.

 

[Precision]

                                                                                 

 

   As Spock would say " May I say that I have not thoroughly enjoyed serving with humans ?  I find their illogical

   and foolish emotions a constant irritant."         

 

                                               

Edited April 10, 2016 by Precision

[Thike Salvmu]

4 hours ago, carlos said:

I obtained 87%. But I disagree with the answers in the test in the two cases where they differ from mine.

 

Well, actually I don't completely disagree with the first one. The fact that Mary was in the crime scene, touched the fatal weapon and got her clothes dirty with blood doesn't prove in itselft that Mary committed the crime. But since there is evidence that no one else entered the crime scene, there is simply no other rational explanation. So even if the reasoning is inductive, I think it's still perfectly valid from a logical viewpoint.

 

Question 12.
A  The man was stabbed to death.
B  Mary was seen leaving the scene of the crime shortly after the time of the murder.
C  Blood found on Mary's trousers was the same as the victim's.
D  Only Mary's fingerprints were found on the murder weapon.
E  No other people were witnessed near the scene of the crime.
F  Mary's DNA was found on the victim's body.
G  The CCTV evidence showed only Mary entering and leaving the victim's flat.

Conclusion
Therefore Mary committed the murder

.

Nowhere is there any evidence that no one else entered the crime scene.

True, there is no evidence that anyone else did enter the crime scene but a lack of available evidence does not prove that it did not happen. Maybe they haven't found the evidence yet.

For example, it is not logical to say:

 

A  No evidence can be found of anyone else entering the crime scene.

B  We have abundant evidence proving that Mary did enter and did leave.

 

Conclusion

Therefore Mary committed the murder

 

There ARE other possible explanations. 

 

In the other case, I think the test is playing games with words. If water is defined as "a molecule composed of two hydrogen atoms and one oxygen atom", then anything with a different composition is not water, no matter if it looks like water or has many or all of water's properties. That logic is faulty.

 

Question 15. 
A  Water is a molecule composed of two hydrogen atoms and one oxygen atom.
B  Every observation or examination by microscope has confirmed this.

 

Conclusion
Therefore we can predict that every future examination of water will reveal the same chemical composition.

 

I don't understand what you mean here. The question is not whether or not anything with a different composition can possibly be water. All you are being asked is whether the conclusion can be logically deduced from the two premises, nothing more.

 

 

Did you get all 15 answers on test 2 correct? 

 

 

Edited April 10, 2016 by Thike Salvmu

[Ahuvah]

I got 8 right in the second test about 53% i think. I'm reallly bad at tests.

[Miss Bea]

I knew I would do badly. 67%. I have never done well on, "thought problems". Never. Perhaps the most logical thing I have done in my life is to be in a position you call, you, dear ones, brother and sister!

[Fiona]

I got 93%. My husband was surprised it was THAT low 😂😂

Sent from my SM-G900I using Tapatalk

[carlos]

4 hours ago, Thike Salvmu said:

Nowhere is there any evidence that no one else entered the crime scene.

True, there is no evidence that anyone else did enter the crime scene but a lack of available evidence does not prove that it did not happen. Maybe they haven't found the evidence yet.

But the last statement was:

G  The CCTV evidence showed only Mary entering and leaving the victim's flat.

If no one else entered and left, no one else could be the murderer. Unless the victim's flat is not the crime scene and then it's just a red herring.

 

4 hours ago, Thike Salvmu said:

I don't understand what you mean here. The question is not whether or not anything with a different composition can possibly be water. All you are being asked is whether the conclusion can be logically deduced from the two premises, nothing more.

Sorry, I think I am not understanding you either. As I see it, any future observation of a water molecule will show two atoms of hydrogen and one of oxygen, because otherwise it wouldn't be water.

 

Let me put it in a different way: By definition all dogs are mammals. So any future dog will be a mammal. If a future dog turned out not to be a mammal, then it wouldn't be a dog, because it falls outside the definition of "dog". Where is the logical fallacy?

 

OK, I did test 2 now and obtained 87% again. I made a mistake in question 2, its wording confused me but I understand why my answer is incorrect. The other is, again, with Mary and the murder. If she was recorded on video stabbing the guy, how is the reasoning inductive?

Edited April 10, 2016 by carlos

[Thike Salvmu]

 

1 hour ago, carlos said:

But the last statement was:

G  The CCTV evidence showed only Mary entering and leaving the victim's flat.

If no one else entered and left, no one else could be the murderer. Unless the victim's flat is not the crime scene and then it's just a red herring.

 

Yes, but it is the 'if' that is the important thing. Just because the CCTV evidence showed only Mary entering and leaving the victims flat does not mean it is a fact that only she did.

 

Sorry, I think I am not understanding you either. As I see it, any future observation of a water molecule will show two atoms of hydrogen and one of oxygen, because otherwise it wouldn't be water.

 

Not necessarily.

 

Let me put it in a different way: By definition all dogs are mammals. So any future dog will be a mammal. If a future dog turned out not to be a mammal, then it wouldn't be a dog, because it falls outside the definition of "dog". Where is the logical fallacy?

 

There is no fallacy here but this is worded differently from the original question.

The original question:

 

Question 15. 
A  Water is a molecule composed of two hydrogen atoms and one oxygen atom.
B  Every observation or examination by microscope has confirmed this.

 

Conclusion
Therefore we can predict that every future examination of water will reveal the same chemical composition.

 

The conclusion is not deductively valid. The second premise doesn't prove anything. The only thing we can say for certain given these two premises is that  water is a molecule composed of two hydrogen atoms and one oxygen atom. What we might be 'able to predict' is irrelevant. It is a REASONABLE conclusion to predict  that every future examination of water will reveal the same chemical composition, but it is NOT a LOGICAL one.

 

OK, I did test 2 now and obtained 87% again. I made a mistake in question 2, its wording confused me but I understand why my answer is incorrect. The other is, again, with Mary and the murder. If she was recorded on video stabbing the guy, how is the reasoning inductive?

 

A deductively valid conclusion leaves no room for doubt. If the premises are true then the conclusion MUST OF NECESSITY be true. It is impossible for it not to be. The fact that Mary was recorded on video stabbing the guy does not prove for certain that she is the one who killed him.

 

 

Edited April 10, 2016 by carlos
removed duplicated quoted text

[Qapla]

From what I could see, their explanations for why some of the questions are considered valid or invalid is not based on the information given.

 

As to Mary killing the man, based "solely" on the information given, there was no more of a "logical" reason to bring Sherlock Holmes into the answer then it would have been to bring Mickey Mouse into the ones about Donald Duck.

 

There were a couple others that they did the same thing ...... so, not so "logical" after all.

[ChocoBro]

Actually, this is quite typical of these logic tests to try and trick you into an intuitive answer instead of a fully logical one.

 

What if Mary's apartment had a secret entrance? Does the data make it clear that CCTV cameras monitor her entire apartment, windows and all? Just an example to show why in this case there is no clear deductive evidence she is the killer. If the test said "a neighbor said he witnessed Mary committing the murder" that would still not be deductive logic, since he could be lying. If the test said "The victims goldfish witnessed Mary stabbing the victim to death" then that would not be a valid witness testimony but on the other hand logical proof of the murder.

 

Of course, in any murder case she would be prosecuted. But the logic tests aren't about being realistic at all, otherwise it wouldn't say "all ducks bark"..

 

 

[Thike Salvmu]

5 hours ago, Qapla said:

From what I could see, their explanations for why some of the questions are considered valid or invalid is not based on the information given.

 

As to Mary killing the man, based "solely" on the information given, there was no more of a "logical" reason to bring Sherlock Holmes into the answer then it would have been to bring Mickey Mouse into the ones about Donald Duck.

 

There were a couple others that they did the same thing ...... so, not so "logical" after all.

The only reason Sherlock Holmes was brought in was to highlight the fact that there are other possibilities. Maybe you are not familiar with his famous quote which goes something along the lines of, "Once you have eliminated the impossible, whatever remains, no matter how improbable, must be the truth."

 

I agree with you that some of the explanations given could have been better but all perfectly logical to me.

[Nobody]

Or the man committed suicide and Mary merely tried to help, thus contaminating the scene.

[Qapla]

The instructions said to base the answers only on the data presented in the question and there was no mention of Holmes in the question 

[carlos]

8 hours ago, Your Brother said:

Or the man committed suicide and Mary merely tried to help, thus contaminating the scene.

But she was recorded on video stabbing the man.

[Thike Salvmu]

2 hours ago, Qapla said:

The instructions said to base the answers only on the data presented in the question and there was no mention of Holmes in the question 

Holmes has nothing to do with the question or the answer. He was brought in to the explanation of why the argument was not a deductively valid one for the reason I mentioned in my previous post.

[Thike Salvmu]

17 minutes ago, carlos said:

But she was recorded on video stabbing the man.

Not on test 1.

[Nobody]

3 hours ago, carlos said:

But she was recorded on video stabbing the man.

Guess I have to read the instructions on why she is not the murderer.  Ya just reread it. 

 

Took the test a second time to get the answers and did worse than the first time? 

[Qapla]

15 hours ago, Thike Salvmu said:

The only reason Sherlock Holmes was brought in was to highlight the fact that there are other possibilities. Maybe you are not familiar with his famous quote which goes something along the lines of, "Once you have eliminated the impossible, whatever remains, no matter how improbable, must be the truth."

 

I agree with you that some of the explanations given could have been better but all perfectly logical to me.

 

OK, if we are going to "bring in" outside information/people/principles to help explain why an answer is considered "valid" or "invalid", as in the one with Mary, since the information given does "logically" present her as the murderer, then we can also do the same for other questions.

 

Take question 7. According to the test, the answer to question 7 is valid

Answer 7.
a) All ducks bark.
Donald is a duck.
- Therefore Donald barks.

Valid

 

However, since I already know that Mickey Mouse can talk, then it does not follow that Donald Barks - he may be able to talk - making the question Invalid

 

This is just as logical as saying that Someone else could have killed the man -

 

Again, going by ONLY the information given in the questions, some of the reasoning used to support the "valid/invalid" conclusions that the test maker(s) twisted used to  determine the score is suspect.

 

Point in practice:

I am a logical person

You agree with me on my stand about this test

 

Therefore: If you disagree with me you are NOT a logical person

Valid

 

[trottigy]

Yeah!!!  

 

 

Remember - this is strictly a LOGIC test - NOT a truthfulness test or Infer test. If the premise statements do not say explicitly what the conclusion statement states - then it is not valid.

 

As an example:

If it states -

1. all dogs will always be animals

2. all dogs are mammals

3. all future animals will be classified as a mammals 

Therefore - all dogs in the future will be mammals - THEN you could say yes.

 

Without all of the about you can only ASSUME that the definition of mammal will not change in the future. 

Edited April 11, 2016 by trottigy

[Thike Salvmu]

19 hours ago, Qapla said:

 

OK, if we are going to "bring in" outside information/people/principles to help explain why an answer is considered "valid" or "invalid", as in the one with Mary, since the information given does "logically" present her as the murderer, then we can also do the same for other questions.

The information given gives a strong inductive argument,  NOT a deductive one.

Take question 7. According to the test, the answer to question 7 is valid

Answer 7.
a) All ducks bark.
Donald is a duck.
- Therefore Donald barks.

Valid

 

However, since I already know that Mickey Mouse can talk, then it does not follow that Donald Barks - he may be able to talk - making the question Invalid

 

This is just as logical as saying that Someone else could have killed the man -

You have me totally baffled here. Please explain your reasoning.

Again, going by ONLY the information given in the questions, some of the reasoning used to support the "valid/invalid" conclusions that the test maker(s) twisted used to  determine the score is suspect.

 

Point in practice:

I am a logical person

To me you seem totally illogical. Maybe I am just misunderstanding you.

You agree with me on my stand about this test

 

Therefore: If you disagree with me you are NOT a logical person

Valid