I scored 100% in this logic test, therefore I'm a fan of Mr. Spock.

[Oldfisti]

See how logical you are...                         http://www.think-logically.co.uk/lt.htm

[Triple J]

100%

[cloud2blue]

I call shenanigans on the last question!

[NAKID]

I got a 93% got the last answer wrong but I call bullshit. The question said:
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 answered Valid because it define water in the first statement...

Their explanation of the answer being Invalid is not consistent with the 2 statements provided...

[Triple J]

The last one could go either way. It says "Therefore we can predict that every future examination of water will reveal the same chemical composition".

Predict is the key word IMO. Since they say predict I see how it is valid. Predictions aren't always correct.
-----------------
I answered invalid for a different reason. The 1st statement gives the molecular composition, not the chemical one...therefore the last statement doesn't make sense as they are predicting the chemical composition, based upon the molecular one.

[I'm no chemist, so I'm not sure if how I perceived the terminology is correct...so my the reasoning for my answer could be off]

[jdubbs32584]

Holy shit. I'm a chick and I got 100%.

A logical chick? Nah, can't be. 

[Mother]

stupid test

[duccarlos]

93%, but I can't figure out which one a missed. I'm a bit sleep deprived right now.

[superjohn]

93% and I agree that the last one is BS.

[He Man]

PREDICTION. THe question is CAN you make a prediction. and you can, since water was defined. The last one is bull shit. Technically speaking, if anyone got that last one right, your all the ones who got 93%. the rest of us who got it wrong are the ones that got 100%. 

Heres the kicker...


"If one defines water as a property that contains two atoms of hydrogen and one atom of oxygen only...."

The first stipulation is "Water is a molecule composed of two hydrogen atoms and one oxygen atom."

[Oldfisti]

The quiz' reasoning for the answer:


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.

Invalid.

Invalid but controversial in philosophical circles. If one defines water as a property that contains two atoms of hydrogen and one atom of oxygen only, then the argument above is valid. However, it is possible also that there may exist a substance that looks like water, boils as water, freezes as water, nourishes plants and life as water, and yet has a different chemical composition to what we know as water. There is nothing that could logically prevent this possibility occurring so the argument then becomes invalid.

[Holden]

I got a 93% got the last answer wrong but I call bullshit. The question said:
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 answered Valid because it define water in the first statement...

Their explanation of the answer being Invalid is not consistent with the 2 statements provided...

93% and I agree that the last one is BS.

There is a difference between inductive and deductive reasoning.

The sun has always risen at sunrise.
Will the sun rise tomorrow?
No one knows!

Just because you have not observed the exception to the rule cannot mean that it does not exist.

The quiz' reasoning for the answer:


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.

Invalid.

Invalid but controversial in philosophical circles. If one defines water as a property that contains two atoms of hydrogen and one atom of oxygen only, then the argument above is valid. However, it is possible also that there may exist a substance that looks like water, boils as water, freezes as water, nourishes plants and life as water, and yet has a different chemical composition to what we know as water. There is nothing that could logically prevent this possibility occurring so the argument then becomes invalid.

This is also right.

[CowboyBeebop]

The quiz' reasoning for the answer:


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.

Invalid.

Invalid but controversial in philosophical circles. If one defines water as a property that contains two atoms of hydrogen and one atom of oxygen only, then the argument above is valid. However, it is possible also that there may exist a substance that looks like water, boils as water, freezes as water, nourishes plants and life as water, and yet has a different chemical composition to what we know as water. There is nothing that could logically prevent this possibility occurring so the argument then becomes invalid.

The problem with this explanation is that it has nothing to do with the statements or the conclusion.  So what if there is another compound that does all the things that water does?  The first statement defines the term "water", and that definition has nothing to do with its properties and everything to do with composition.  If water is H20, then any examination of water will reveal two hydrogen atoms and one oxygen atom.  The substance is not defined by its label - "water" - its label is defined by the substance's composition.   

If you want some real logic fun, try taking the LSAT.

[NAKID]

There is a difference between inductive and deductive reasoning.

The sun has always risen at sunrise.
Will the sun rise tomorrow?
No one knows!

Just because you have not observed the exception to the rule cannot mean that it does not exist.

Not a fair analogy in this case. You didn't DEFINE what the sun is composed of. They did in the first place, therefore, by calling it "water" at any time will still mean it is comprised of 2 H and 1 O atoms.

[somegirl]

Another 100% chick here.