Answer: 2 minutes
Step-by-step explanation:
According to the book, ''Guesstimation: Solving the World's Problems on the Back of a Cocktail Napkin'', on average, everyone picks their noses for 2 minutes each day.
This figure is simply a reasonable compromise between the least and highest amount of time that people can spend picking their nose in a day as well as the assumption that everyone does it.