A fun logic puzzle to get you through humpday.
A boy and a girl are talking. The person with black hair says, "I am a boy". The person with white hair says, "I am a girl". At least one of them lied.
Who is the boy and who is the girl?
A fun logic puzzle to get you through humpday.
A boy and a girl are talking. The person with black hair says, "I am a boy". The person with white hair says, "I am a girl". At least one of them lied.
Who is the boy and who is the girl?
Permalink: http://problemotd.com/problem/boy-or-girl/
Content curated by @MaxBurstein
Comments:
Migwell - 10 years, 7 months ago
Black hair- girl White hair- boy
We are given that there is 1 girl and 1 boy. "At least one of them lied" means that 1 or BOTH of them could have lied.
Only 1 lied: black haired "boy" is lying. Therefore there are two girls: 1 black hair and 1 white hair. Contradiction. (There are 1 boy and 1 girl)
white haired "girl" is lying. Therefore there are 2 boys: 1 white/black hair each. Also a contradiction.
Both of them lied: They swapped each other's gender. Black haired "boy" person is actually a girl. White haired "girl" is actually a boy.
reply permalink
Max Burstein - 10 years, 7 months ago
Nice job!
reply permalink
Pearce Keesling - 10 years, 7 months ago
Both of them have to be lying, because if only one of them is lying then they are the same gender which isn't possible. This means that girl has black hair, and boy has white hair.
reply permalink