Bonnie bought a bag of birdseed. She left it in her apartment (#5) before she went to work, intending to fill the feeder that afternoon. But when she got back, the bag of birdseed was gone!
There were four other people living in the same apartment building as her, all of whom were avid birdwatchers like Bonnie. One of them must have done it. Look at the clues below. If you know everybody's name, apartment number (#1 through #4), and favourite bird, you will know who is guilty.
1. The guilty person's apartment number is not numbered one higher or one lower than Hal's.
2. Joe's favourite bird is the crow; his apartment number is one lower than that of Ike (who doesn't like robins).
3. The guilty person's apartment is not #3 (the number of the finch-lover's).
4. Gil is neither at apartment #1 nor the wren-lover.
From (3)-> finch-lover lives in ap #3 (a) .
From (2)->Joe loves crows (b).
From (a) and (b) -> Joe must live in #4 (c1) or Joe must live in #1 or #2(c2)
We suppose (c1) is correct ,and using (2)-Ike is above Joe- implies Ike lives at #5 (impossible)-> (c1) is false
That means that (c2) must be true.
From (c2) and (2) -> Joe lives at #1, Ike lives at #2(d1) or
Joe lives at #2 and Ike lives at #3(d2).
That means that only one (d1 or d2 ) is true for sure.
It doesn't matter in this moment if (d1) is true or (d2) is true,-
, for us to be sure that #2 is already taken by Ike or by Joe (e), and that means for sure that Gil can't live at #2, and neither does Hal.(f)
From (1) Hal has to have neighbours and that means that he can live only in "#2 or #3" (g1) or in "#4"(g2)
But (g2) must be wrong because it would mean that the whole first sentence is obsolete, it would say that #5-the victim is not the thief, and I already know it-, and without this sentence,at least in this certain case- with Hal in #4 - ,we wouldn't have enough clues to solve the problem.
So, (g1) must be true: Hal lives at #2 or #3, but using (f)->Hal must live at #3. Using(3) Hal is innocent and he is finch-lover.(h)
From (4)->Gil doesn't live in #1 and using (f),(h)->Gil can only live at #4(i)
So, using (h),(2)->Ike lives at #2 and Joe at #1.
From(4) Gil is not the same person as the wren lover, so Ike must be the wren-lover.(j),because everyone already loves another kind of bird.
(And even if the wren-lover is not Ike,but Gil the order of the apartaments is exactly the same, so it wouldn't change anything)
From(4) wren-lover doesn't live at #1 either and is true because he is Ike and Ike lives at #2 (or Gil, and lives at #4).
So, until now we' ve got:
#2-Ike,wren-lover( or not)
#3-Hal, finch-lover,not guilty
#4-Gil, maybe robin-lover( or wren-lover)
Using (1), the only possible thief is Joe.
(1) tells me that the thief is not the immediate neighbour of Hal, so I could imagine that the thief is Joe, Hal himself or the victim, Bonnie #5.
But because Hal lives at #3 that makes him not guilty, so, it must be Joe or Bonnie.
But Bonnie is not guilty from the beginning so the thief is Joe.
Posted by cezar
on 2004-11-17 13:46:42