Logic Riddles

Question: A man goes into a barbershop and gets a $15 haircut. He pays the barber with a $20 bill, but the barber doesn't have change because it is an especially slow day. The barber goes to the flower shop next to his own and trades the $20 bill for a $10 dollar bill and two $5 bills. Then he gives the man his $5 in change.

Later the lady from the flower shop confronts the barber and tells him that the $20 bill he gave her was counterfeit. The barber agrees and he gives the lady a different $20 bill.

Later that day he tries to figure out how much money he lost. What did he lose?

Question: What do you call 2 Us?

Question: A man hangs his hat and walks 500 yards with his eyes closed. He then turns around and shoots his hat with his pistol with his eyes still shut.

How did he do this?

Question: A horse travels a certain distance each day. Strangely enough, two of its legs travel 30 miles each day and the other two legs travel nearly 31 miles. How is this situation possible?

Question: My first is in yesterday, but not in today; My second is in after, but not in before; My third is in start, and also in stop; My fourth is the 20th letter of the English alphabet; My fifth is in correct but not in wrong; and my sixth is in pretty, but not in cute. My whole is something celebrated by Christians. What is this teaser referring to?