Logic Riddles

Question: There is a one story house. The walls are blue, the floor is pink, the stove and cupboards are red. What color are the stairs?

Question: If you count 20 houses on your right going to the store and 20 houses on your left coming home, how many houses did you count?

Question: What relation would your father's sister's sister-in-law be to you?

Question: A man is twenty years old but has only had five birthdays. How is that possible?

Question: A man in prison has a visitor. Afterward a guard asks the inmate who the visitor was to him. The inmate replies: "brothers and sisters I have none, but that man's father is my father's son." Who was the visitor to the inmate?