Grades 5-6 Video Solutions 2025-2025_5-6

Video Transcription

Number 24. Felix never tells the truth on Tuesdays, Thursdays, and Saturdays. He always tells the truth on the other four days. One day, Mateo had the following conversation  with Felix. Mateo, what day is it today? Felix, Saturday. Mateo, what day will it be tomorrow? Felix, Wednesday. On which day did this conversation take place? Pause if you want to  try and solve it. Okay, so the first thing that we can notice is that Felix has to be on one of  the lying days because he said that today is Saturday and tomorrow is Wednesday. That's  obviously not true, so he is lying, which means that it is either Tuesday, Thursday, or Saturday,  right, because it's one of the lying days. And since he's lying and he said it's Saturday,  that means it's not Saturday because he's lying, so it can't be Saturday. And then he said that  tomorrow is Wednesday. Well, he must be lying, and if tomorrow was Wednesday, today would be  Tuesday, but he's lying, so today is not Tuesday. It can't be Tuesday, which means that the only  day left that it could be is Thursday, right, because he must be lying and it can't be Tuesday,  it can't be Saturday, so it has to be Thursday. So this conversation took place on Thursday, so that's option E, or D, excuse me.

Video Summary

The conversation between Mateo and Felix took place on a lying day for Felix, which occurs on Tuesdays, Thursdays, and Saturdays. Felix claimed it was Saturday and that the next day would be Wednesday, both of which were lies. Since it couldn't be Saturday or Tuesday, the only remaining option is Thursday. Therefore, the correct day of this conversation is Thursday.