Girl and Boy Puzzle - Solution

The Puzzle:

Girl and Boy
A boy and a girl are talking.

"I am a boy" - said the child with black hair.

"I am a girl" - said the child with white hair.

At least one of them lied. Who is the boy and who is the girl?

Our Solution:

They both lied.

The child with the black hair is the girl, and the child with the white hair is the boy.

(If only one lied they would both be boys or both be girls)
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