Most, but perhaps not all, of these involve fallacious reasoning: false alternatives (FA), false cause
(FC), or hasty generalization (HG).  Do a diagram, indicate which step is fallacious, identify the
fallacy, and then explain why the fallacy is present.  If no fallacy . . . then say so!

1. [  1   Oh, Western U.S. cities are all so very dull and uninteresting, so different from what it's like
here in Boston].  I know, because [  2   I once spent a weekend with my sister in Salt Lake City].
[  3   It was a terribly dull and uninteresting place].

   2  +  3         Invalid, weak.  HG: Only one thing, Salt Lake City, is given as a basis for concluding
        |                                            that many things (all Western cities) are dull.
       1

2. [  1   Most students who take PHI 110 do so to satisfy general education requirements]. In fact, [   1   over 90% take it for that purpose].  Since [  2   Jon Simms is taking it this semester], [  3   he must be taking it as a general ed requirement].

      1   +    2      Invalid but strong.   No fallacy.
            |
           3

3. [   1    You can have me change your oil filter now for $10], or [   2   I can fix your engine damage from a dirty filter later for several hundred dollars]. [   1   You can pay me now], or [  2  you can pay me later]!  [   1    You'd better let me change your oil filter today].

     1 or 2   +   not 2 (unstated but assumed)
                  |             DD, valid
                 1
FA: There are more reasonable alternatives than the two given in the reasons, for example, you could change the filter youself, or take your car somewhere else.  It is obviously an assumption of the arguer that you prefer paying $10 over paying several hundred.  No inference indicator, but it's clear what the intended conclusion is.

4. [   1   Every major war that we have had for the last hundred years occurred when a Democratic
administration was in power].  [   2    Electing Democrats to the presidency, therefore, is likely to result in our country going to war].

        1  -->  2      Invalid, weak      FC: That major wars and Democratic administrations have been
                                                        associated (occurred together) doesn't show what caused the wars.  More likely causes are things like aggression, international crises, etc.
 

5. If [  1   the fire was caused by a faulty chimney] then [   2   the builder is legally liable for the house burning down].  But it turned out that [  not 1   the fire was due to bad wiring], which shows that [  not 2    the builder isn't legally liable after all].

     if  1  then  2  +  not 1         DA, invalid, weak
                     |
                not 2

The builder could have been, and typically is, responsible for all the work done.  It could thus also be true that if the fire was due to bad wiring then the builder is liable.  Of course it is possible that for some reason the builder isn't liable for the wiring.  But showing that a conclusion is possibly true is very different from showing that it is true.  This argument's conclusion says that he isn't liable, not that he might possibly not be!