Five children — Ivan, Sylvia, Ernie, Dennis, and Linda — entered a candy store, and one of them stole a box of candy from the shelf.
Afterward each child made three statements:
Ivan:
1. I didn’t take the box of candy.
2. I have never stolen anything.
3. Dennis did it.
Sylvia:
4. I didn’t take the box of candy.
5. I’m rich and I can buy my own candy.
6. Linda knows who the crook is.
Ernie:
7. I didn’t take the box of candy.
8. I didn’t know Linda until this year.
9. Dennis did it.
Dennis:
10. I didn’t take the box of candy.
11. Linda did it.
12. Ivan is lying when he says I stole the candy.
Linda:
13. I didn’t take the box of candy.
14. Sylvia is guilty.
15. Ernie can vouch for me, because he has known me
since I was a baby eight years ago.
If each child made two true and one false statement, who stole the candy?
If Ivan did it, all three of his statements would be lies. Ivan didn't do it.
If Sylvia did it:
Ivan's statement numbered 3 could be his lie.
Sylvia's statement numbered 4 could be her lie.
Ernie's statement numbered 9 could be his lie.
Dennis' statement numbered 11 could be his lie.
Linda's statement numbered 15 could be her lie.
These are consistent.
If Ernie did it:
Ivan 3 could be his lie.
Either Sylvia 5 or 6 could be her lie.
Ernie would be making at least two lies: 7 and 9.
It can't be Ernie.
If Dennis did it:
Dennis' 10 and 11 would both be lies.
Dennis didn't do it.
Likewise if Linda did it: 13 and 14 would both be lies.
Linda didn't do it.
Sylvia stole the candy.

Posted by Charlie
on 20170612 13:56:57 