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On a "prime date," both the month and the day are prime numbers. For example, Feb.7 or 2/7 is a prime date. How many prime dates occurred in 2007? If you could please provide an explanation as well!

 Aug 18, 2022
 #1
avatar+2446 
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There are 5 "prime months" (2, 3, 5, 7, 11)

 

For the dates, there are 12 (2, 3, 4, 5, 7, 11, 13, 17, 19, 23, 29, 31)

 

So there are \(5 \times 12 = 60\), but we overcount for 2/29, 2/31, and 11/31, so there are \(60 - 3 = \color{brown}\boxed{57}\) "prime dates".

 Aug 18, 2022
 #2
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A slight typo in your dates. Should read: [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]==11 dates

 

Feb/2007 =2007 was NOT a leap year, and therefore Feb/2007 had only 28 days ==9 prime dates

 

So: Feb + Mar + May + Aug + Nov ==9 + 11 + 11 + 11 + 10==52 prime dates.

Guest Aug 18, 2022
 #3
avatar+2446 
+1

o yea, forgot 4 was composite lol 

 

and also i already accounted for feb 29 and feb 31 

 Aug 18, 2022

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