Nearly all mail that is correctly

Answer choices

1. A

   Too Strong: a large proportion21% picked this

   A large proportion of the mail that is correctly addressed is

   We couldn't prove that there was any damaged mail that was correctly addressed. If we knew that correctly addressed mail sometimes took 3 or more days to arrive, then we could prove it was damaged, but the statements don't tell us that any correctly addressed mail has taken 3 or more days to arrive. The first sentence definitely leaves room for that, since it says "nearly all correctly addressed mail arrives within two days", so there is probably a sliver of correctly addressed mail that takes longer and thus was damaged in transit. But we wouldn't be able to say that it's "a large proportion". If you got "nearly all" of the cake, then I got "almost none" of the cake, not a large proportion.

   21%
2. B

   Illegal Opposite6% picked this

   No incorrectly addressed mail arrives within two business days of

   This takes what we know: correctly addressed ? almost always w/in 2 days and illegally flips it into: incorrectly addressed ? never w/in 2 days We're never allowed to infer from A ? B that not A ? not B

   6%
3. C

   Unknown Group: most 2-day mail32% picked this

   Most mail that arrives within two business days of being sent

   We have no way to talk specifically about 51% or more of mail that arrives within 2 days. We know that some of that 2-day mail is correctly addressed. But some of it could be incorrectly addressed too. And we don't know the ratio of correctly addressed to incorrectly addressed mail. If I said "Nearly all men who are Senators are very informed about politics. Overall, however, most men are not informed about politics", can we infer that (C) most men that are informed about politics are Senators? Of course not. The relative group size can be way different (most of 100 Senators could be 51 or higher, whereas not-most of 100 million males could be 49 million), so there's no way to judge what percentage of the politically informed are in one group or the other.

   32%
4. D

   Correct38% picked this

   A large proportion of mail is

   Why this is right

   At first we might think, "This doesn't have to be true. Yes, we know that most mail takes 3 or more days, but that doesn't have to be because it's incorrectly addressed. It could be that it's correctly addressed but damaged in transit." Here's the problem with that -- if we tell ourselves that "most correctly addressed mail is damaged in transit, and thus takes more than 2 days", then we'd be contradicting the first sentence, which says that "nearly all correctly addressed mail arrives within 2 days". If all mail were correctly addressed, then this paragraph would contradict itself. If there were 100 pieces of mail, all correctly addressed, we know that nearly all (we'll say 90 of them) get there within 2 days. That leaves 10 pieces of correctly addressed mail not getting there within 2 days. But we were told that "most pieces of mail" take more than 2 days. 10 is not most of 100. We'd have to keep adding incorrectly addressed mail in order to be able to every honor the idea that most total mail takes more than 2 days. ? pieces of mail 100 correctly addressed ? incorrect 90 arrive w/in 2 days 10 take more than 2 (damaged in transit) Let's say we added in 50 incorrectly addressed pieces of mail. 150 pieces of mail 100 correctly addressed 50 incorrect 90 arrive w/in 2 days 10 take more than 2 (damaged in transit) Even if all 50 of those took more than 2 days, and we added in the 10 correctly addressed ones that took more than 2 days, we'd still only be at 60 pieces that took more than 2 days. And 60 is not most of 150. It's less than half. So we'd have to add even more incorrectly addressed pieces of mail. 180 pieces of mail 100 correctly addressed 80 incorrect 90 arrive w/in 2 days 10 take more than 2 (damaged in transit) Now we could have a total of 90 pieces of mail that took more than 2 days (80 + 10). 90 out of 180 is exactly half, so we'd still need to go a little higher with our incorrectly addressed total to make the "most" fact work. No matter what number of mail pieces we make the correctly addressed mail, we'll always have the problem that 90% of it gets there within 2 days and only 10% or less takes more than 2 days. In order to comply with the fact that more than 50% of all mail takes more than 2 days, we need to add a lot of incorrectly addressed mail to make the math work. "Large proportion" doesn't have a specific numerical cut-off, but it looks like we'll always need more than 40% of the mail to be incorrectly addressed in order to make all this math work, and more than 40% is definitely "a large proportion".

   Skill tested: Must be True · how this choice captures the argument's function is the move to repeat next time.

   38%
5. E

   Unsupported Comparison3% picked this

   More mail arrives within two business days of being sent than arrives between two and three business

   For the same reason we couldn't pick (C), we can't pick this. Without knowing the overall ratio of correctly addressed mail to incorrectly addressed mail, we can't do any specific comparisons of which quantities are more. The language of this answer is not mathematically airtight, but it seems to be saying that more mail arrives in "0 to 2.0 days" than in "2.1 to 3.0 days". When we talk about mail and days, we only talk about it in terms of integers. We don't have the post office tell us that our letter will get there in 2.3 days. Mail is only delivered once a day to our house, so if someone sent it on Tuesday and we get it on Thursday, we'd say it was two business days after it was sent. If we get it on Friday, it would be three business days. What would be the delivery situation where it's between two and three business days? So in addition to us not being able to compare quantities of mail, the numbers here are a little silly.

   3%