Riddle me this!

[kefira]

If D always goes before B and E then the highest position E will ever occupy is third

I was referring to this line. B can go before E, likewise, E can go before B, so long as they are both after D. E could possibly occupy the 2nd position. Answer "D" still isn't viable, but not due to E being forced into the third position.

. . . . .

mayerling, did you get the same answer I did for your bridge riddle? (As in, are we both wrong the same way?)

 

[mayerling]

I got answer C
Could somebody explain how you get B?

 

[kefira]

I wrote it in my spoiler..

 

[mayerling]

Here's one that I couldn't even begin to figure out on my own and DH had to work it out for me. Good thing is that after doing so many I'm getting better at figuring out how to solve them.

An apartment building has five floors. Each floor has one or two apartments. There are exactly eight apartments in the building. The residents of the building are: A, B, C, D, E, F, G, H and each person lives in their own apartment.

A lives on a floor with two apartments.
B lives on the floor directly above G.
The second floor has only one apartment.
D and E live on the same floor.
F doesn't live on the same floor as H.
C lives in the only apartment on his floor.
H lives on the first or second floor.

Question 1: Which of the following statements is always true?
a. H lives on the third floor.
b. C does not live on the fourth floor.
c. E does not live on the second floor.
d. A lives on the first floor.

Question 2: If D lives on the fourth floor, which of the following statements is always false?
a. F lives on the fifth floor.
b. A lives on the first floor.
c. C lives on the second floor.
d. H lives on the third floor.

 

[davi_el_mejor]

Here's one that I couldn't even begin to figure out on my own and DH had to work it out for me. Good thing is that after doing so many I'm getting better at figuring out how to solve them.

An apartment building has five floors. Each floor has one or two apartments. There are exactly eight apartments in the building. The residents of the building are: A, B, C, D, E, F, G, H and each person lives in their own apartment.

A lives on a floor with two apartments.
B lives on the floor directly above G.
The second floor has only one apartment.
D and E live on the same floor.
F doesn't live on the same floor as H.
C lives in the only apartment on his floor.
H lives on the first or second floor.

Question 1: Which of the following statements is always true?
a. H lives on the third floor.
b. C does not live on the fourth floor.
c. E does not live on the second floor.
d. A lives on the first floor.

Question 2: If D lives on the fourth floor, which of the following statements is always false?
a. F lives on the fifth floor.
b. A lives on the first floor.
c. C lives on the second floor.
d. H lives on the third floor.

 

[kefira]

I guess I won't spoiler anymore, since I'm not sure you're seeing it anyway?

This one is super easy with careful reading. For Q1, it is always true that E can't live on the 2nd floor, since it only has one apartment (rule 3), and E & D live on the same floor (rule 4). For Q2, it is always false that H lives on the 3rd floor, since rule 7 says that H lives on the 1st or 2nd floor.

 

[sonnyjane]

Here's one that I couldn't even begin to figure out on my own and DH had to work it out for me. Good thing is that after doing so many I'm getting better at figuring out how to solve them.

An apartment building has five floors. Each floor has one or two apartments. There are exactly eight apartments in the building. The residents of the building are: A, B, C, D, E, F, G, H and each person lives in their own apartment.

A lives on a floor with two apartments.
B lives on the floor directly above G.
The second floor has only one apartment.
D and E live on the same floor.
F doesn't live on the same floor as H.
C lives in the only apartment on his floor.
H lives on the first or second floor.

Question 1: Which of the following statements is always true?
a. H lives on the third floor.
b. C does not live on the fourth floor.
c. E does not live on the second floor.
d. A lives on the first floor.

Question 2: If D lives on the fourth floor, which of the following statements is always false?
a. F lives on the fifth floor.
b. A lives on the first floor.
c. C lives on the second floor.
d. H lives on the third floor.

As the others said, this one is actually pretty easy, not because you can figure out where everyone lives, but because you can easily eliminate where they DO NOT live.

 

[mayerling]

Sorry everyone. I've fallen victim to the typo issue. The last condition is that H does not live on the first or second floor.

 

[kefira]

In that case, the answer for Q2 is C (Q1 is solved the same as before). If you put D & E on floor 4, and C on floor 2, there is nowhere left to place B one floor above G.

 

[mayerling]

In that case, the answer for Q2 is C (Q1 is solved the same as before). If you put D & E on floor 4, and C on floor 2, there is nowhere left to place B one floor above G.

Yup! That's what the answer booklet says as well. I'll be back with more.

 

[VapidLapid]

This reminds me of thethe following scene from the Hepburn /Tracy movie "Desk Set"/

Tracy: Now, A train started out at Grand Central... with X passengers aboard and a crew of nine.

At 10th Street four got off and nine got on.

At White Plains, three got off and one got on.

At Chappaqua nine got off and four got on.

And at each successive stop thereafter...nobody got off, nobody got on till the train reached its next-to-the-last stop, where five people got off and one got on. Then it reached the terminal."

Hepburn: That's easy. Eleven passengers and a crew of nine.

Tracy: Uh, w...That's not the question.

Hepburn: I’m sorry.

Tracy: How many people got off at Chappaqua?"

Hepburn: Nine.

Tracy- That's correct.

Hepburn - Yes, I know.

Tracy: Uh, would you mind telling me how you arrived at that conclusion?

Hepburn: Spooky, isn't it? Did you notice that there are also nine letters in "Chappaqua"?

Tracy: Are you in the habit of associating words...with the number of letters in them?

Hepburn: I associate many things with many things.

Tracy: I see. Hmm.

Hepburn: Aren't you going to ask me how many people got off at White Plains? Three.

Tracy: But there are ten letters in White Plains.

Hepburn: No. Eleven.

Tracy: But only three got off there.

Hepburn: You see, I've only ever been to White Plains...three times in my whole life.

Tracy: Well, supposing you'd only been there twice.

Hepburn: But I wasn’t. I was there three times. Aren't you gonna ask me how many people got on at Croton Falls?

Tracy: There is no Croton Falls mentioned at all in the question.

Hepburn: No, but it is the next-to-the-last stop on that line. Anyway, one.

 

[mayerling]

Okay, this one is from an old LSAT and neither DH nor I have been able to figure it out.

There are 3 recycling centres: Centre 1, Centre 2 and Centre 3. Exactly 5 kinds of materials are recycled at these centres: glass, newsprint, plastic, tin, and wood. Each centre recycles at least two but no more than three materials. The following conditions must hold:
a. Any recycling centre that recycles wood must also recycle newsprint.
b. Every kind of material that Centre 2 recycles is also recycled at Centre 1.
c. Only one of these centres recycles plastic, and that centre does not recycle glass.

Question: If Centre 1 is the only recycling centre that recycles wood, then which one of the following could be a complete and accurate list of the kinds of material that one of the recycling centres recycles?
A. plastic, tin
B. newsprint, wood
C. newsprint, tin
D. glass, wood
E. glass, tin

 

[0-0-0]

If Centre 1 is the only recycling centre that recycles wood, Centre 1 must recycle wood and newsprint due to condition a. Only Centre 3 can recycle plastic due to condition b and c, and the fact that each centre recycles at least two but no more than three materials. Centre 1 and 2 must recycle glass as a result. Only Centre 3 can recycle tin.

Centre 1
wood
newsprint
glass

Centre 2
newsprint
glass

Centre 3
plastic
tin

Answer is A.

 

[mayerling]

If Centre 1 is the only recycling centre that recycles wood, Centre 1 must recycle wood and newsprint due to condition a. Only Centre 3 can recycle plastic due to condition b and c, and the fact that each centre recycles at least two but no more than three materials. Centre 1 and 2 must recycle glass as a result. Only Centre 3 can recycle tin.

Centre 1
wood
newsprint
glass

Centre 2
newsprint
glass

Centre 3
plastic
tin

Answer is A.

Thanks for this. Although, I'm not sure I understand the logic behind saying that Centre 3 must recycle plastic due to condition b and c. Why can't it recycle glass instead?

 

[kefira]

Thanks for this. Although, I'm not sure I understand the logic behind saying that Centre 3 must recycle plastic due to condition b and c. Why can't it recycle glass instead?

Hope it's ok to jump in here. Center 3 has to recycle plastic because only one place can recycle plastic. The one place can't be Center 2, because everything at Center 2 is also at Center 1. If the one place were Center 1, it would have 3 items already (wood, newsprint, plastic), and Center 2 would only have 1 (newsprint). Nothing else could be added at Center 2 without breaking the 3 item limit in Center 1. Therefore, Center 3 is the only place to recycle plastic.

 

[mayerling]

Thanks for this. Although, I'm not sure I understand the logic behind saying that Centre 3 must recycle plastic due to condition b and c. Why can't it recycle glass instead?

Hope it's ok to jump in here. Center 3 has to recycle plastic because only one place can recycle plastic. The one place can't be Center 2, because everything at Center 2 is also at Center 1. If the one place were Center 1, it would have 3 items already (wood, newsprint, plastic), and Center 2 would only have 1 (newsprint). Nothing else could be added at Center 2 without breaking the 3 item limit in Center 1. Therefore, Center 3 is the only place to recycle plastic.

Thanks, Kefira. I think I understand now. Why can't centre 3 recycle plastic, tin and newsprint?

 

[kefira]

It could. But the question you have to answer is "which one of these lists of materials could a Center process?" Because we can rule out answers B-E, A is the answer, even though it's not the definitive answer to "what materials does Center X (Center 3, in this case) process?" I hope that makes sense. I tried to word it more clearly, but I made it worse, so I changed it back!

 

[mayerling]

I see!