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 Post subject: Did one of the three members of a certain team
 Post Posted: Sat Aug 30, 2008 7:17 pm 
Did one of the three members of a certain team sell at least 2 raffle tickets yesterday?

(1) the 3 members sold a total of 6 raffle tickets yesterday
(2) No 2 of the members sold the same number of raffle tickets yesterday

During the test, I was confused with the way the problem was written. I did not clearly understand what "did one of the three" meant.

Anyways, I am thinking the question is asking if at least one of the three sell at least 2 tickets. With this assumption, I think this is the solution. Tutors, please correct if wrong

(1) if they sold 6 together, the possibilities (2,2,2), (1,2,3), (0,3,3) (different variations of these). In all cases, there is at least one with 2 or more.

(2). This I think is real cool.. if one of them is 0, the other is 1, the third one has to be 2 or more, hence sufficient.

Hence the answer is D.

I got this wrong in the exam.

-Raj.


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 Post subject: Did one of the three members of a certain
 Post Posted: Mon Sep 01, 2008 5:59 am 
1) Sufficient as even if 1 member sold 0 ticket, one member must have sold atleast 2 tickets as total sold tickets is 6.
2) Not sufficient because number of tickets sold is not given.

So answer should be B.
What is the correct answer.


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 Post subject: Re: Did one of the three members of a certain
 Post Posted: Wed Sep 03, 2008 5:26 pm 
Answer is D.

for 2), this is sort of tricky.. even if two of them sold the lowest possible 0 and 1, the third one has to sell at least 3 since they all sold different number of tickets. You dont actually have to know the total number. Hope that clarifies..
-Raj.

TakingGMAT wrote:
1) Sufficient as even if 1 member sold 0 ticket, one member must have sold atleast 2 tickets as total sold tickets is 6.
2) Not sufficient because number of tickets sold is not given.

So answer should be B.
What is the correct answer.


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 Post subject:
 Post Posted: Fri Sep 26, 2008 6:46 am 
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ManhattanGMAT Staff


Posts: 7146
yeah, this should be (d).

statement (1):
there's a statement called the pigeonhole principle, which basically says the following two things:
* if the AVERAGE of a set of integers is an INTEGER n, then at least one element of the set is > n.
* if the AVERAGE of a set of integers is a NON-INTEGER n, then at least one element of the set is > the next integer above n.
this principle is easy to prove: if you assume the contrary, then you get the absurd situation in which every element of a set is below the average of the set. that is of course impossible.

specifically, statement (1) is a case of the first part of the principle: the average of the set is 6/3 = 2, so at least one element of the set must be 2 or more.
again, you can prove this by reductio ad absurdum: if no one had sold 2 or more tickets, then you'd have a set in which everyone sold either 0 or 1 ticket, but the average is somehow still 2. that's untenable.

--

statement (2):
there are only two ways not to sell at least 2 tickets: sell 0 tickets, and sell 1 ticket.
if everyone sells a different # of tickets, then you can't fit three people into these two categories.
therefore, someone must have sold at least 2 tickets.


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