AMC 12A 2012 #9
Posted:
Fri Jun 15, 2012 9:36 pmby nsguy1350
A year is a leap year if and only if the year number is divisible by 400 (such as 2000) or is divisible by 4 but not 100 (such as 2012). The 200th anniversary of the birth of novelist Charles Dickens was celebrated on February 7, 2012, a Tuesday. On what day of the week was Dickens born?
Re: AMC 12A 2012 #9
Posted:
Sat Jun 16, 2012 12:31 pmby darksaber21
Okay, on this one, every year we go back moves that date back by one day and each leap year moves the day back two days, since:
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So, within the span of the 200 years, and since leap years happen pretty much every four years, then it would be predicted that there is 50 leap years within the 200 year period. Now, to exclude any non-leap years that is divisible by four, like 1900, we now have:
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Since: [unparseable or potentially dangerous latex formula] [unparseable or potentially dangerous latex formula], we move Tuesday back four days, which makes the answer Friday.