2013 General Problem 21
Source:
February 4, 2013
Problem Statement
How many positive three-digit integers can represent a valid date in , where either corresponds to a month and corresponds to the day in that month, or corresponds to a month and corresponds to the day? For example, 202 is a valid representation for February 2nd, and 121 could represent either January 21st or December 1st. (Note: During the actual test they had to write the number of days in each month so don't feel bad if you have to google that :P)