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PrepTest 49, Section 4, LR 24

Posted: Fri Jan 22, 2010 4:32 pm
by s1m4
#24

Can somebody please explain why A is correct, and how other choices could be eliminated? (B is easy to eliminate, but the others not so much.)

Very tough parallel flaw question..

Re: PrepTest 49, Section 4, LR 24

Posted: Fri Jan 22, 2010 5:16 pm
by Cambridge LSAT
A simple example with numbers will help to illustrate the flaw:
# of employees: 100
# of employee computer programmers: 51
# of computer programmers (total): 20,000
# of computer programmers with excellent salaries: 10,001
# of computer programmers without excellent salaries: 9,999

All the computer programmers at this company could belong to the set of computer programmers who don't have excellent salaries.

Similarly in choice A, none of the numbers are given, so there is no way to know for certain that the two sets overlap.
# of Molly's classmates: 25
# of Molly's classmates who are gardeners: 13
# of gardeners (total): 20,000
# of gardeners with a great deal of patience: 10,001
# of gardeners without a great deal of patience: 9,999

Re: PrepTest 49, Section 4, LR 24

Posted: Fri Jan 22, 2010 5:33 pm
by chewdak
Another "most" question.
We know "most" just means "majority" or over 50%.
The stimulus simplified reads:
Most A are B.
Most B have C.
Therefore at least one A has C.
This is faulty as explained above by cambridgelsat.
(A) parallels the structure above
(B) changes structure by using "some" instead of "at least one"
(C) changes conclusion so that it becomes 'Therefore at least one A, who is B, has C'.
(D) Changes premise from 'Most A are B' to "Most B in A are D"
(E) This one is actually true, not what we are looking for.

Re: PrepTest 49, Section 4, LR 24

Posted: Fri Jan 22, 2010 5:39 pm
by s1m4
thx guys !!