Question

If the argument below is valid, name which of the four valid forms of argument is represented. If it is not valid, name the fallacy that is represented.

If the water is filtered, then it does not contain lead.
The water contains lead.
Therefore, the water is not filtered.

Answer 1

have you see something in your book around the lines, "if p then q, p therefor q"? Or Modus Ponens?

Answer 2

you lost me

Answer 3

it's an argument form. Look up Modus Ponens in your book.

Answer 4

im looking

Answer 5

it dont show

Answer 6

http://en.wikipedia.org/wiki/Modus_tollens
http://en.wikipedia.org/wiki/Modus_ponens
And there are a lot more than the above two.

You have to come up with a way to make a P and Q from the above argument. So here, it looks like this:
\[\huge p \rightarrow q\]\[\huge \neg q\]\[\huge \therefore \neg p\]

Does that help a bit more? I know that these can be tricky and i'm not 100% sure i'm right.. just like 90 something % sure. :D

Answer 7

is this good

Answer 8

the four valid forms are:


MODUS PONENS

If p is true, then q is true
p is true
therefore q is true


MODUS TOLLENS


if p is true, then q is true.
q is not true.
therefore p is not true


DILEMMA


either p or q are true
if p is true, then r is true.
if q is true, then r is true.
therefore r is true.


SIMPLIFICATION


p and q are true
therefore p is true


Of the 4 forms, I believe MODUS TOLLENS fits the best.


p is equal to "if the water is filtered then it does not contain lead"
q is equal to "it does not contain lead"
therefore the water is not filtered.


this is fairly obvious because if the water was filtered it would not contain lead.


if p is true then q is true
q is not true (the water contains lead)
therefore p is not true.

Answer 9

Modus Tollens does fit best indeed. I had mentioned it in my post but decided to remove it and i'm glad i did because you figured it out on your own! :D

Answer 10

thank you