Logic test

[Targ]

14/15. Got caught on the very last one, the water one.

Same here.

I found it painful to click invalid on "therefore all kangaroos are marsupials" ... I wanted to say ... "but, but, they are!"

 

[Wiccan_Child]

I found the water one to be tricky because I didn't know if the authors had taken the 'future observations may be false' thing into account. Overthinking!

 

[3sigma]

Take this test, post your score. Be honest. Jesus knows when you're lying.

I scored 100% on both tests. It’s easy. You just have to read what’s written, believe it and think literally. Wait, what? That doesn’t sound right.

 

[sfs]

100% on both tests. The second one was more interesting.

 

[Bushido216]

15/15

This is just sentential and monadic predicate logic. You could easily symbolize the first 10 or so if you'd felt like it.

 

[3sigma]

The second one was more interesting.

Yes it was.

There was a strong temptation to think inductively rather than deductively on some of the questions, particularly question 6. Premise (g) almost had me.

Question 14 was tricky as well because of the ambiguity.

I chuckled at question 5. I’d like a dollar for every time I’ve heard some variation of that.

 

[Tinker Grey]

15 for 15

 

[AV1611VET]

0 for 15

They were trick questions, anyway.

I guess I could say I got 100% --

 

[Avatar]

0 for 15

They were trick questions, anyway.

I guess I could say I got 100% --

You're funny AV, I've missed you. How have you been?

 

[AV1611VET]

You're funny AV, I've missed you. How have you been?

Hey, buddy!

Good to see ya!

Welcome back!

 

[Avatar]

Thanks!

 

[AV1611VET]

Thanks!

You betcha!

I told Chrisbot: 'this one's for Avatar' when I passed his record --

 

[Avatar]

You betcha!

I told Chrisbot: 'this one's for Avatar' when I passed his record --

Wow, you did it?! I can't find the members list anywhere so I have no idea what the standings are. Congrats man!

 

[kharisym]

Got 15 of 15 correct, while ill and not thinking clearly.

 

[Nathan45]

Answer 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.

Invalid. The syllogism itself is invalid and can only be considered as a strong inductive argument and not deductive. It is the 'we can predict' part of the conclusion which comes from nowhere, so the argument is not strictly formal. There is an ongoing debate within philosophical circles as to whether water must conform to the molecule H2O. Some argue that it is logically possible for a substance to appear exactly as water and yet still be of a different chemical composition.

This is a stupid test. First of all, Premise B is irrelevent, there is no inductive reasoning. The conclusion that whatever is being examined is water follows from (A) alone.

In the first place: If whatever is in the microscope doesn't have this chemical composition then it is not water by definition, according to (a). Which would imply that the premise is valid, except...

In the second place: Just because the material is water doesn't mean it will appear to be water in the examination. The examination could be flawed. so the premise is invalid, except...

the conclusion states "We can predict". We can predict anything, just because it's not 100% correct doesn't mean we can't predict it. So the conclusion is valid regardless of the premises.

 

[sfs]

This is a stupid test. First of all, Premise B is irrelevent, there is no inductive reasoning. The conclusion that whatever is being examined is water follows from (A) alone.

In the first place: If whatever is in the microscope doesn't have this chemical composition then it is not water by definition, according to (a). Which would imply that the premise is valid, except...

In the second place: Just because the material is water doesn't mean it will appear to be water in the examination. The examination could be flawed. so the premise is invalid, except...

the conclusion states "We can predict". We can predict anything, just because it's not 100% correct doesn't mean we can't predict it. So the conclusion is valid regardless of the premises.

No, the conclusion is true, regardless of the premises. The argument is valid (which is what is in question) only if the conclusion is implied by the premises, which it is not.

 

[Nathan45]

No, the conclusion is true, regardless of the premises. The argument is valid (which is what is in question) only if the conclusion is implied by the premises, which it is not.

I think you got me there Since the premises say nothing about the prediction powers of anyone...

 

[SithDoughnut]

100%

If only real life worked like this test.

 

[ug333]

100%

Me loves me some logic

 

[metherion]

100%. Woot. Then again, I have a bit of an edge... despite never having taken a logic class, both my parents teach it at college and took a vested interest in raising me with it. I think them for it a lot. And that 100% is only for part 1, I will edit in part II's score later.

Edit: 14, 93%. The one about Mary murdering this time tripped me up, because I thought that the CCTV evidence showing her stabbing the guy would tip the school to 'therefore Mary committed the murder' compared to the first one. But I suppose it could have been tampered with to show that she did it when she didn't, so... yeah. Whoops.

Metherion