Octopus Logic

Relevant wiki: Truth-Tellers and Liars

All of the octopuses cannot be lying, or else there would be $7 \times 4 = 28$ legs, and the Black one would be telling the truth (a contradiction).

Since all of the octopuses have given different answer, we know that three of the four must be lying. This means that these three have 7 tentacles each (21 between them) and hence the truth telling octopus will have either 6 or 8 tentacles bringing the total to either 27 or 29. No one said 29, so they must have 27 legs.

They are only 4 octopuses and only one of them said the truth. That means that 3 of them have 7 legs and the 4th has either 6 or 8 legs.

7+7+7+8=29 --> no one said 29.

7+7+7+6=27 --> only the Green one said it!

Only one servant is telling truth and thus each of the others has 7 legs. Therefore the 4 servants have 27 or 29 legs altogether.

Since, they all have different answers as to the total number of legs, only one is telling the truth. Thus, three of them are liars. 3 * 7(liar servant) = 21. So the possible total number of legs is 27 xor 29. Since 27 appears and 29 does not, 27 is the total and the honest one is the green servant.

I just added the legs together from the black, yellow, green and red octopuses in the picture. Why over complicate things?

as three give answer 7 legs which lying and only one give right 6or8 so 21+6=27or 21+8=29 which is not offered in question

HAHAHA I just counted their legs and green just have 7 legs so he's the one that must be lying \m/

I just counted the legs and the one with eight is the one I choose because it was an actual octopus

Based on their stories, there must be one 6 legged or one 6 legged. The rest should all be 7 legged liars because they've got different answers. So that will be 7 x 3 = 21. Since the choices are only limited, so we need to eliminate 8 since 21+8 = 29 w/c is not part of the choice. there's only one who mentioned 27 and that is green.

3 out of 4 are lying.. means 3 have 7 legs- total legs=21 , now the 4th will have either 6 or 8 means total should be 27 or 29... 29 is no option, hence 27 is the answer

There is at most 32 legs and at least 24.

4 are 6 legged = 24 legs

4 are 7 legged = 28 legs

From this information, you can tell that there is 1 octopus that said the truth. This means if there is a octopus that has ether 6 or 8 legs, and the rest have 21 legs.

If the octopus had 8 legs, the total number of legs is 29, and if the octopus had 6 legs, the total number of legs is 27.

This means the green octopus is telling the truth.

Here's the way I did it. I have multi-headed dragons and slightly different colors and did it with a C-like computer program.

http://primepuzzle.com/tunxis/matyconn.tc

Here's the output.

There are 27 total heads.

The blue dragon is a liar and has 7 heads. The red dragon is a liar and has 7 heads. The green dragon tells the truth and has 6 heads. The yellow dragon is a liar and has 7 heads.

3/4 lying, (7's, so 21) + one truth (6 or 8).. 29 isn't an option so 27 it is

I just counted the arm things in the picture

The hint is in the clue- only one spoke the truth! The only choice that allows it would be 7 * 3 + 6 = 27

Count the number of legs in the picture . They equal 27, so the green one is right. Simple.

The answer is green because 27/7 = 21 which means 27 - 21 = 6 and we know that octopus with 6 legs is truthful hence answer.

I counted the number of tentacles shown of the given colored octopuses and got 27

If only one must be telling the truth then that means the other 3 are lying

Which will be interpreted as

$3\times7=21$

Now we either add 6 or 8

So the answer should be 27 or 29

Lol my 8 yr old counted the legs of all the octopuses that were colored in the picture and said the answer is green. He's been playing this game and getting all the answers right and comes up with crazy ways on how he gets them... unbelievable.

This might only works for this situation, but you know there is at least one liar, so there are initially 7 legs. With three other octopuses, there could be two with 6 legs or two with 8 legs and the corresponding opposite would be 8 or 6 respectively. So the possible out comes are 27, or 29 legs total. We can eliminate the even numbered options because there is at least one liar meaning the answer would have to be odd numbered. 27 is the only option given. Definitively, however, Michael Lee's answer is most right. If I had originally assumed and concluded from my deductions that there were three liars, the only possible answers are 27 and 29.