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10/3/2015 7:44:47 PM

Posts: 2
One day, six people (A, B, C, D, E, and F) came to the library returned a volume of the encyclopedia (12, 13, 14, 15, 17 or 19). Each person then checked out a different volume of one of the returned by the other five people.

Here are the clues:
1. E returned the volume that was checked out by the person who returned #13
2. The volume C returned is numbered exactly 2 lower than the volume that was checked out by the person who returned the book that C checked out.
3. The volume that the F returned (which was checked out by E) is numbered exactly 1 lower than the volume E returned.
4. The volume that D checked out has a lower number than the one F checked out.
5. The A checked out the book that was returned by the person who checked out #14

Here is what I'm thinking (wish there was a spoiler blocker or something)


Clue 2.
Takes B and C and they basically swap volumes (17 & 19)

Clue 1.
If 'E' returns 15, F returns 14 (due to clue 3.) and E than checks out 14. (Clue 3)

Clue 5.
Since E checks out 14, than A checks out 15 (due to clue 1 and 5)

Clue 4 needs 'D' to check out a book lower than F and only 12 & 13 remain, so it seems logical to pick 12 for D, but than that also leaves D to return book 12 and that is not possible due to the initial instruction.

I've played with this a several different ways, I'd even dare say all possible, but if all possible ways were tried, this would have been solved. wink I wonder if there is an error, but looked for some errata and did not notice one. My guess is I have made an error with clue 2 and using this as a criss-cross type switch but since person B is never mentioned outside the initial instructions, and C is only mentioned in clue 2, it seemed correct to place those two together. Additionally, they each check out each others returned book and there is a 2 number difference which gets negated by any other option if I read everything correctly.

Open for suggestions!


10/3/2015 9:17:44 PM

Posts: 705
I solved the logic problem. You are correct in your assumptions about Clues 1 and 5. And the fact that Clue 2 refers to B and C. But incorrect that B and C exchanged volumes. B returned what C checked out (same number). C returned 2 lower than what B checked out (different numbers). Hope this helps.
edited by Frances on 10/3/2015

10/3/2015 10:34:05 PM

Posts: 2

I will give that a go and hope to have success with it!

I trust you are correct, and appreciate the nudge!


Indeed, you are correct and I misread clue 2! Everything fell into place, thank you!
edited by wansu on 10/3/2015

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