How many weeks in 2013 -?

Answer 1

There is no single, well-defined answer to this type of question, because it depends on how exactly you define a week, i.e., how you define what is the first week and the last week of the year.

EDIT: Since there are 365 days in 2013, there are 52 weeks and one day in every year - except leap years (when there's an extra day)

Answer 2

52