# Which octopus spoke the truth?

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It is known that octopuses with 7 legs always lie, while those with 6 legs and those with 8 legs always tell the truth. One night, four octopuses met:

Black — 'We have 28 legs.'
Green — 'We have 27 legs.'
Yellow — 'We have 26 legs.'
Red — 'We have 25 legs.'

Who spoke the truth?

posted Aug 17, 2015

+1 vote

27 legs
Of the 4 octopuses at least 3 lie. These three have 7 legs each = 21 legs. If the 4th octopus also has 7 legs, the total is 28 legs, but all octopuses must lie. This black octopus says 28 legs, so this is not the case. If the 4th octopus has 8 legs, the total is 29 legs, but no octopus says that, meaning all must lie. This can also not be true. If the 4th octopus has 6 legs, the total is 27 legs. The green octopus is then the only one who speaks the truth.

Similar Puzzles

King Octopus has servants with six, seven, or eight legs.
The servants with seven legs always lie, but the servants with either six or eight legs always say the truth.

One day, four servants met.
The blue one says: "Altogether we have 28 legs";
the green one says: "Altogether we have 27 legs";
the yellow one says: "Altogether we have 26 legs";
the red one says: "Altogether we have 25 legs".

What is the colour of the servant that says the truth?

+1 vote

Shahrukh says truth only one day in a week.
Hint 1: Days are Sun, Mon and so on.
Hint 2: One day he says “I lie on Mon and Tue”.
Hint 3: Next day he says “Today is either Thu, Sat or Sun”.
Hint 4: next day he says “I lie on Wed and Fri”.
On which day he says the truth?