I was asked this recently and got it right away. Apparently it was designed by a psychologist to be a riddle that serial killers usually answer correctly but "normal" people don't. Sorry if it's a repost, yes I searched.
*edit* Ok, the psychologist part is a hoax I guess. It's still an interesting riddle though.
A woman named Jane has a mother who dies. She attends her mother's funeral and at the funeral she meets a man named John. John and Jane seem to be the perfect match for one another in every way and they talk for a few minutes but end up parting their separate ways without exchanging any contact information. Soon after, Jane kills her sister. What was Jane's motive for killing her sister?
*edit* Ok, the psychologist part is a hoax I guess. It's still an interesting riddle though.
A woman named Jane has a mother who dies. She attends her mother's funeral and at the funeral she meets a man named John. John and Jane seem to be the perfect match for one another in every way and they talk for a few minutes but end up parting their separate ways without exchanging any contact information. Soon after, Jane kills her sister. What was Jane's motive for killing her sister?