Short Riddles and Answers

Question: What occurs once in a minute, twice in a moment and never in one thousand years?

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

Question: What 3 positive numbers give the same result when multiplied and added together?

Question: Why would a hair stylist rather cut the hair of two brunettes than one red head?

Question: I have a foot on either side of me and one in the middle.

What am I?