63 replies to this topic

[lulu1221]

the lion lies on mon-wed and the rest of the week he tells the truth. His statement has two parts. The first one says he was "lying yesterday" which means that he would need to have said it on Thursday, the second says he will be lying again "two days after tomorrow" since he said it on Thursday then he would be lying again on Sunday and Sunday is not a lying day. Therefore, the statement is not true and he must have said it on Monday, Tuesday or Wednesday.

I tried to explain it as clear as I could, sorry if I just made it more confusing

[Jules McWyrm]

Wow - hot damn, people.

Logical conjunction is well defined. It doesn't matter what you imagine it to mean. All this opining on the definition of "AND" makes no more sense than arguing about the meaning of addition. Get over it.

Beyond grasping basic logical connectives, maybe read up on DeMorgan's Law, as well.

It's really simple.

A: the Lion was lying yesterday.
B: the Lion will be lying three days from now.

The Lion made the statment "A /\ B". That statment is NEVER TRUE. So it is always false. So the lion could make that statment on any day he was lying. Simple as that.

Applying DeMorgan's Law, we start with the original statment (A /\ B), negate it ( ~(A/\B) ), and convert it by applying the law ( ~A\/~B ). The lion can make this statment on any day that (~A\/~B) evaluates to TRUE.

[cinnimini]

the day the music died ooorrrr monday

[Malfure]

monday

[Vishmi]

The answer should be Monday

[Vishmi]

On second thoughts I think this statement can be made on a Monday, Tuesday or a Wednesday. Because this statement can be false if one is true and the other one is false or if both are false.

Edited by Vishmi, 24 April 2008 - 07:19 AM.

[wow213]

did any1 notice 'forrest of forgetfullness'

[boen]

... as you say, Lion made a joke on Monday, or Tuesday or Wednesday,
or, as Larryhl says, it can also be Thursday (if two days after tomorrow is Monday),
or I forgot about "Forest of forgetfullness"?

Edited by boen, 21 May 2008 - 10:00 PM.

[mikedotcom]

Lion and Unicorn II. - Back to the Logic Problems
Alice came across a lion and a unicorn in a forest of forgetfulness. Those two are strange beings. The lion lies every Monday, Tuesday and Wednesday and the other days he speaks the truth. The unicorn lies on Thursdays, Fridays and Saturdays, however the other days of the week he speaks the truth.
Lion said: Yesterday I was lying and two days after tomorrow I will be lying again.
Which day did he say that?

Spoiler for Solution

Lion and Unicorn II. - solution
This conjunction is true only if both parts are true. The first part is true only on Thursday, but the second part is a lie then (Sunday is not a lying day of the Lion). So the whole statement can never be true (at least one part is not true). Therefore the Lion could have made the statement on Monday, on Tuesday and even on Wednesday.

Spoiler for but then...

I don't think the lion could have said that Tuesday because he said yesterday (Monday) I was lying...but that is TRUE, therefore could not have made that claim on a Tuesday (or Wednesday). Monday is the only day his statement is true-true

[dreinick]

The answer has to be monday.

just because both halfs of the sentence are true does not make it the only answer.
if it were tuesday then half of the sentence would be false making the whole derivation false.