10/3/2015 7:44:47 PM
wansu 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. 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 crisscross 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!
Wan
