Good Riddles

Question: A young woman is attending her mother's funeral. While there, she meets a man she has never seen before and falls in love immediately. After the funeral she tries to find him but cannot. Several days later she kills her sister.

Why does she kill her sister?

Question: What building has the most stories?

Question: What stays where it is when it goes off?

Question: What English word is as long as it is valued?

Question: If 1/2 of 5 is 3, then what is 1/3 of 10?