Guest Posted May 5, 2008 Report Share Posted May 5, 2008 May 5th is a palindromic date, because it can be written 5/5. Ignoring the slash, 55 is a palindromic number, written the same forwards and backwards. Ignoring year, how many palindromic dates are there? List them all. (Careful, no leading zeroes to any months or days!) Careful! This is a harder riddle than it initially appears! Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 1/1 1/11 1/21 1/31 2/2 2/12 2/22 3/3 3/13 3/23 ahh, sorry, gotta run Quote Link to comment Share on other sites More sharing options...
0 HoustonHokie Posted May 5, 2008 Report Share Posted May 5, 2008 May 5th is a palindromic date, because it can be written 5/5. Ignoring the slash, 55 is a palindromic number, written the same forwards and backwards. Ignoring year, how many palindromic dates are there? List them all. At first, I was trying to figure out if the "/" was part of the palindrome, or if it was ignored. Rather than ask questions, I answered it both ways. If "/" is part of the palindrome, I get: 11 dates: 1/1 2/2 3/3 4/4 5/5 6/6 7/7 (my b-day!) 8/8 9/9 11/11 12/21 If it's just the number, I get: 32 dates: 1/1 1/11 1/21 2/2 2/12 2/22 3/3 3/13 3/23 4/4 4/14 4/24 5/5 5/15 5/25 6/6 6/16 6/26 7/7 (still my b-day!) 7/17 7/27 8/8 8/18 8/28 9/9 9/19 9/29 10/1 11/11 12/1 12/21 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 At first, I was trying to figure out if the "/" was part of the palindrome, or if it was ignored. Rather than ask questions, I answered it both ways. If "/" is part of the palindrome, I get: 11 dates: 1/1 2/2 3/3 4/4 5/5 6/6 7/7 (my b-day!) 8/8 9/9 11/11 12/21 If it's just the number, I get: 32 dates: 1/1 1/11 1/21 2/2 2/12 2/22 3/3 3/13 3/23 4/4 4/14 4/24 5/5 5/15 5/25 6/6 6/16 6/26 7/7 (still my b-day!) 7/17 7/27 8/8 8/18 8/28 9/9 9/19 9/29 10/1 11/11 12/1 12/21 forgot 11/1 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 forgot 11/1 You came up with 33 dates. 33 dates is the best answer with thinking inside the box. However, I've come up wth at least 17 other answers, for a total of 50. Remember, the slash does NOT matter, otherwise, I could have come up with a WHOLE lot more. No more hints for now! Where am I (perfectly legitimately) getting 17 more answers from? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 Isn't 34 dates the "inside the box" answer, given that 1/31 is not on that list? You came up with 33 dates. 33 dates is the best answer with thinking inside the box. However, I've come up wth at least 17 other answers, for a total of 50. Remember, the slash does NOT matter, otherwise, I could have come up with a WHOLE lot more. No more hints for now! Where am I (perfectly legitimately) getting 17 more answers from? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 You have roman numerals in mind? Then 1/6, 4/1, 9/1, 5/4, 6/5, 6/4, 8/5, 7/4, 8/4, 10/9, 11/10, 11/9, 12/10, 12/9, 10/20, 9/21You came up with 33 dates. 33 dates is the best answer with thinking inside the box. However, I've come up wth at least 17 other answers, for a total of 50. Remember, the slash does NOT matter, otherwise, I could have come up with a WHOLE lot more. No more hints for now! Where am I (perfectly legitimately) getting 17 more answers from? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 (edited) However, I've come up wth at least 17 other answers, for a total of 50. Remember, the slash does NOT matter, otherwise, I could have come up with a WHOLE lot more. No more hints for now! Where am I (perfectly legitimately) getting 17 more answers from? 10/1 11/1 12/1 13/1 14/1 15/1 16/1 17/1 18/1 19/1 20/2 21/2 22/2 23/2 24/2 25/2 26/2 27/2 28/2 29/2 30/3 31/3 we can add 22 more (edit: only in a leap year, lest we'd have to remove the extra day) Edited May 5, 2008 by ChuckJerry Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 33 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 we can add 22 more (edit: only in a leap year, lest we'd have to remove the extra day)10/1 11/1 12/1 13/1 14/1 15/1 16/1 17/1 18/1 19/1 20/2 21/2 22/2 23/2 24/2 25/2 26/2 27/2 28/2 29/2 30/3 31/3 Except the 11th of January and the 22nd of February are already counted. I like your answer, though. I didn't think of that. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 You came up with 33 dates. 33 dates is the best answer with thinking inside the box. However, I've come up wth at least 17 other answers, for a total of 50. Remember, the slash does NOT matter, otherwise, I could have come up with a WHOLE lot more. No more hints for now! Where am I (perfectly legitimately) getting 17 more answers from? I have 51 answers... unless I've duplicated one somewhere: Month-Day 1/1 1/11 1/21 1/31 2/2 2/12 2/22 3/3 3/13 3/23 4/4 4/14 4/24 5/5 5/15 5/25 6/6 6/16 6/26 7/7 7/17 7/27 8/8 8/18 8/28 9/9 9/19 9/29 10/1 11/1 11/11 12/1 12/21 Day-Month 10/1 12/1 13/1 14/1 15/1 16/1 17/1 18/1 19/1 20/2 21/2 23/2 24/2 25/2 26/2 27/2 28/2 31/3 Borrowing slightly from other posts. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 There are only 33 palindromic dates in a year if you use the Month-Day format without using any leading zeros. The only way you can get more is by using tricks such as using Day-Month, roman numerals etc... which is essentially repeating the same date in a different way, so it shouldn't count... Please correct me if I am wrong.... Quote Link to comment Share on other sites More sharing options...
0 itachi-san Posted May 5, 2008 Report Share Posted May 5, 2008 You have roman numerals in mind? Then 1/6, 4/1, 9/1, 5/4, 6/5, 6/4, 8/5, 7/4, 8/4, 10/9, 11/10, 11/9, 12/10, 12/9, 10/20, 9/21 If you're going to use roman numerals there are WAY more, and I also don't think this is intended because it makes for more than 50 total. 1/2, 1/3, 2/1, 2/3, etc... adds up to a lot more than 50 total. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted May 5, 2008 Report Share Posted May 5, 2008 Thinking European was my solution for the extra ones. I like the Roman numeral idea though. Nice job ChuckJerry and everyone else! Quote Link to comment Share on other sites More sharing options...
Question
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May 5th is a palindromic date, because it can be written 5/5. Ignoring the slash, 55 is a palindromic number, written the same forwards and backwards.
Ignoring year, how many palindromic dates are there? List them all.
(Careful, no leading zeroes to any months or days!)
Careful! This is a harder riddle than it initially appears!
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