Logic Riddles

Question: A man is writing his will and he wants to leave everything he has to one of his two sons, whichever one is more dedicated. To decide which one will win his fortune he gives them each a car and tells them that whoever's car passes the finish line he has set up last will get everything he has.After a month of both sons refusing to cross the line they finally go to their uncle for advice. They both leave their uncles house in a hurry and race to the finish line as fast as they can.What advice did their uncle give?

Question: You are my brother, but I am not your brother. Who am I?

Question: There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?

Question: As I was going to St. Ives,
I met a man with seven wives,
Each wife had seven sacks,
Each sack had seven cats,
Each cat had seven kits:
Kits, cats, sacks, and wives,
How many were there going to St. Ives?

Question: If you have 30 white socks, 22 black socks, and 14 blue socks scattered across the floor in the dark, how many would you have to grab to get a matching pair?