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Nearly all mail that is correctly addressed arrives at its [#permalink]
02 Oct 2009, 04:45
Question Stats:
25% (02:03) correct
74% (02:02) wrong based on 39 sessions
Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. In fact, correctly addressed mail takes longer than this only when it is damaged in transit. Overall, however, most mail arrives three business days or more after being sent. If the statements above are true, which one of the following must be true?
A) A large proportion of the mail that is correctly addressed is damaged in transit.
B) No incorrectly addressed mail arrives within two business days of being sent.
C) Most mail that arrives within two business days of being sent is correctly addressed.
D) A large proportion of mail is incorrectly addressed.
E) More mail arrives within two business days of being sent than arrives between two and three business days after being sent.
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Oooh, an LSAT question. Most correctly addressed (CA) mail ---> 2 days or less CA Damaged in transit ---> More than 2 days Most mail takes more than 2 days D is the correct answer. Mail only takes longer than 2 days if it is damaged (and CA) or if it is incorrectly addressed. Since nearly all CA mail is < 2 days, we know that most mail being delivered is incorrectly addressed.
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E seems to be correct. Nearly all correctly addressed mail reaches within 2 days. Most of the mail reaches in 3 or more days. So, not much mail reaches in 2-3 days. This implies that more mail reaches in 2 or less days than does in 2-3 days.
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rkassal wrote: E seems to be correct. Nearly all correctly addressed mail reaches within 2 days. Most of the mail reaches in 3 or more days. So, not much mail reaches in 2-3 days. This implies that more mail reaches in 2 or less days than does in 2-3 days. Nearly all CA mail reaches within 2 days. Say we have 100 pieces of mail. Most mail (>50%) arrives in more than 3 days. 51 pieces are either incorrectly addressed or damaged. 49 pieces are correctly addressed. So either a majority of the mail is damaged and correctly addressed or it is incorrectly addressed. Only the latter is an answer choice. OA is D. I checked my old LSAT prep test. E is wrong because you can't assume that not much mail arrives in 2-3 days. What if 90% of correctly addressed is damaged and takes 3 days? But 95% of mail is incorrectly addressed?
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hitman4683v1 wrote: Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. In fact, correctly addressed mail takes longer than this only when it is damaged in transit. Overall, however, most mail arrives three business days or more after being sent. If the statements above are true, which one of the following must be true?
A) A large proportion of the mail that is correctly addressed is damaged in transit. - Might not be true. It is possible that a large portion of the mails are addressed incorrectly.
B) No incorrectly addressed mail arrives within two business days of being sent. - Agressive statement. It cannot be inferred from the passage.
C) Most mail that arrives within two business days of being sent is correctly addressed. - Correct.
D) A large proportion of mail is incorrectly addressed. - Might not be true. It is possible that a large portion of the mails which are correctly addressed is damaged in transit.
E) More mail arrives within two business days of being sent than arrives between two and three business days after being sent. - No such referrence in the paragraph. Very good question. What is OA?
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OA is D
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Actually I too dont know the answer. Picked it up from a certain forum, where there was a big argument for the same... I too feel the answer to be C. Here is my explanation:
C - Mails that arrive in 2days should be correctly addressed and not damaged ones. In other words, if a mail has reached in 2 days then it is correctly addressed and not damaged and that is what is the option. The premise states clearly that if a mail is damaged it will take greater than 2 days. I am not considering incorrectly addressed mails at all since, the time taken for them hasnt been mentioned at all D - The starting sample space could very well be anything a. All mails correctly addressed b. All mails incorrectly addressed c. Any mixture between a and b D would surely hold true for "b", never for "a" and in certain cases for "c" (E.g: % of incorrect mails exceeds 60% of total and the rest is all correct mails with no damage it would fail when Incorrect percentage is say 25% and correct+undamaged is 37.5%(50% damaged of 75% correct mails)) Therefore, unlike option C, D doesn't satisfy the must be true criterion stated in the question stem fully
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Re: C Most of the mail arriving within 2 days could be incorrectly addressed. This confuses sufficient and necessary conditions. If the mail is correctly addressed then most will arrive within 2 days. If it doesn't arrive within 2 days it was not correctly addressed. This is the contrapositive and the key to the problem. Since the majority of the mail didn't arrive within 2 days it is incorrectly addressed. D. We know that the majority of mail that is correctly addressed is undamaged per the stimulus so this isn't really an issue. Does this help?
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hypermeganet wrote: Re: C
Most of the mail arriving within 2 days could be incorrectly addressed. This confuses sufficient and necessary conditions.
If the mail is correctly addressed then most will arrive within 2 days. If it doesn't arrive within 2 days it was not correctly addressed. This is the contrapositive and the key to the problem.
Since the majority of the mail didn't arrive within 2 days it is incorrectly addressed. D.
We know that the majority of mail that is correctly addressed is undamaged per the stimulus so this isn't really an issue.
Does this help? Could you please elaborate more on why not 'C' C states most of the mail delivered within 2 Business days are correctly addressed which is try Lets take a sample out of 100 mails, since most mails arrive greater than 3 days out of 100 , most of the mails should incorrectly addressed - agreed, which is given by D Consider C which says most of the mail delivered within 2 business days are correctly addressed. If D is true then C is true as well.
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hypermeganet wrote: Re: C
Most of the mail arriving within 2 days could be incorrectly addressed. This confuses sufficient and necessary conditions.
If the mail is correctly addressed then most will arrive within 2 days. If it doesn't arrive within 2 days it was not correctly addressed. This is the contrapositive and the key to the problem.
Since the majority of the mail didn't arrive within 2 days it is incorrectly addressed. D.
We know that the majority of mail that is correctly addressed is undamaged per the stimulus so this isn't really an issue.
Does this help? But arent we then neglecting a whole case where the mail is incorrectly addressed?? The contrapositivity may be true but is not a necessity/surety under this circumstance, due to existence of alternate reasons....
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There are 2 causes of failure of mail delivery: 1.Incorrect address. 2.Damage in transit. Considering above we cannot definately conclude D. So, IMO C is more appropriate..any comments..?
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I will try and do my best to answer this one again. Since this is LSAT logic it is really far more advanced than anything you'll see on the GMAT. I'm getting -0 CR on my GMAT practices and this problem is probably 10 times harder than anything I've seen in GMAT prep. Let's break down the stimulus: Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. If mail is correctly addressed then it arrives within 2 days. If mail does not arrive within 2 days it is not correctly addressed. In fact, correctly addressed mail takes longer than this only when it is damaged in transit.If correctly addressed mail does not arrive within 2 days then it is damaged. Overall, however, most mail arrives three business days or more after being sent. If the statements above are true, which one of the following must be true?So we know that if mail is correctly addressed it arrives within 2 days unless it is damaged. We also know that nearly ALL correctly addressed mail arrives within 2 days, meaning that most correctly addressed mail is NOT damaged. How else can we account for the fact that mail takes longer than 2 days? It must be incorrectly addressed. D. So, why is C wrong? C) Most mail that arrives within two business days of being sent is correctly addressed. This is what is called a mistaken reversal. If mail is correctly addressed then it arrives within 2 days, per above. This does NOT mean that if a letter arrives within two days it is correctly addressed! That is a key point. The stimulus says the only way mail CAN TAKE LONGER is for it to be damaged or incorrectly addressed. This does not mean that incorrectly addressed mail MUST take longer than two days. For all we know 100 letters are delivered, 99 of which are incorrectly addressed. 19 of these letters arrive within 2 days and 81 arrive after 2 days. Only one of these is correctly addressed but the majority take 3+ days.
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i agree with you now..thnks for good explaination!
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Thanks for the explanation hypermeganet Now it makes sense.... Kudos!!!
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C is apparent answer and trap... D is the answer as explained in detail by hyper
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hitman4683v1 wrote: Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. In fact, correctly addressed mail takes longer than this only when it is damaged in transit. Overall, however, most mail arrives three business days or more after being sent. If the statements above are true, which one of the following must be true?
A) A large proportion of the mail that is correctly addressed is damaged in transit.
B) No incorrectly addressed mail arrives within two business days of being sent.
C) Most mail that arrives within two business days of being sent is correctly addressed.
D) A large proportion of mail is incorrectly addressed.
E) More mail arrives within two business days of being sent than arrives between two and three business days after being sent. why not A?
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I chose the wrong answer on this one. But I now see why the answer is D. CA mail consists of two groups: (1) damaged and (2) not damaged mail. At any rate, nearly all of the CA mail arrives at its destination within 2 days. However, Since most of the mail takes longer, it must be the case that the it is not addressed correctly.
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Yup C is not correct. A=>B, then we can say NOT(B)=>NOT(A) but we cannot say B=>A ( mistaken reversal )
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I really think that answer must be A. There is no information about incorrectly addressed mails. So, we we CAN NOT conclude that incorrect mails arrive three days or more. Only A fit. What is the source of OA? ngoctraiden1905 wrote: hitman4683v1 wrote: Nearly all mail that is correctly addressed arrives at its destination within two business days of being sent. In fact, correctly addressed mail takes longer than this only when it is damaged in transit. Overall, however, most mail arrives three business days or more after being sent. If the statements above are true, which one of the following must be true?
A) A large proportion of the mail that is correctly addressed is damaged in transit.
B) No incorrectly addressed mail arrives within two business days of being sent.
C) Most mail that arrives within two business days of being sent is correctly addressed.
D) A large proportion of mail is incorrectly addressed.
E) More mail arrives within two business days of being sent than arrives between two and three business days after being sent. why not A?
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Uhm... I agree with bsv180985. vote for A
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