This is an easy one. Let's first write it out in a manner which indicates
what each person thinks (J = John, A = Alice, F = Frank).
The first clue is that since A and F have claimed the opposite thing, they
both can't be telling the truth, and they both can't be lying. So one of A or
F is telling the truth. This means J must be lying (only ONE person can tell
the truth, remember). If J is lying, then A has the sweets. If A has the
sweets, then F is telling the truth and A is lying, and it's all consistent.
- J: ~A
- A: ~J & ~A
- F: J | A
WWW Maven: Dan
Send me feedback