A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?
A man is found dead with a knife in his back When the investigation is done. A chair lays beside him and the forensic team finds moisture around the body.
What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?