Question 30
Six-legged, seven-legged and eight-legged octopuses serve Neptune, the king of the sea. The seven-legged ones always lie and the six-legged and eight-legged ones always speak the truth. One day four octopuses meet. The blue one says: “We have 28 legs altogether.” The green one says: “We have 27 legs altogether.” The yellow one says: “We have 26 legs altogether.” The red one says: “We have 25 legs altogether.” What colour is the octopus that speaks the truth?