Alice is walking throught the forest of forgetfulness. She wants to know what day of the week it is. She stops and asks a lion and a unicorn. Now the lion lies all of the time on Monday, Tuesday, and Wednesday. The unicorn always lies on Thursday, Friday and Saturday. Alice asks the lion what day it is, he says, “Well, yesterday was one of my lying days.” Alice can’t figure it out just from the lion’s answer so she asks the unicorn and the unicorn says, “Yesterday was also one of my lying days.” What day is it?
Answer: The answer of this riddle is Thursday. Do not be intimidated by this riddle because it is long. Let’s explain it easily! If on Thursday they both claim to lie the day before: it’s Thursday today, so the unicorn must be lying now. Thus, the unicorn lied on Wednesday. The lion must be telling the truth now, right? Accordingly, the lion should have lied on Wednesday. This does not contradict any of the information given in the riddle, as the lion actually lies on Wednesdays. So yesterday is Wednesday and today is Thursday.