Comments on: Finish this sequence of equalities… http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/ Computer Scientist and Open Scholar: Databases, Information Retrieval, Business Intelligence. Tue, 07 Feb 2012 23:39:16 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: man from Georgia http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-54558 man from Georgia Sat, 09 Jul 2011 19:54:13 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-54558 we must count balls. consider 7662 here are 2 balls in 66 also 1111 here is no balls :)))))))) we must count balls.

consider 7662 here are 2 balls in 66

also

1111 here is no balls :) )))))))

]]> By: Sammy http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50723 Sammy Mon, 02 Mar 2009 00:17:21 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50723 First Betti number of the collection of digits, thought of as a topological space! First Betti number of the collection of digits, thought of as a topological space!

]]> By: Paranoid http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50556 Paranoid Wed, 14 Jan 2009 01:36:12 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50556 (am I sexist or just psychologically well-educated?) (am I sexist or just psychologically well-educated?)

]]> By: Paranoid http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50555 Paranoid Wed, 14 Jan 2009 01:35:01 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50555 "My wife solved it" is much too great of a hint. Took about two seconds to solve it after I read that. :) “My wife solved it” is much too great of a hint. Took about two seconds to solve it after I read that. :)

]]> By: Kevembuangga http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50553 Kevembuangga Tue, 13 Jan 2009 09:23:49 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50553 Just a few words of rambling on that. "Salience of artifacts upon a shifted representation of the problem" The question remains, how do we (usually) spot the fruitful representation? Just a few words of rambling on that.
“Salience of artifacts upon a shifted representation of the problem”
The question remains, how do we (usually) spot the fruitful representation?

]]> By: David http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50544 David Mon, 12 Jan 2009 17:42:04 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50544 I challenged a friend with this problem and he answered: "just count the number of circles found on the left". I prefer his solution to mine. I challenged a friend with this problem and he answered: “just count the number of circles found on the left”.

I prefer his solution to mine.

]]> By: David http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50541 David Mon, 12 Jan 2009 01:31:51 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50541 2581 = 2 map 0, 6, and 9 to a value of '1' map 8 to a value of '2'. map any other digit to '0' sum up mapped digit values of the left number and you obtain the number on the right. examples: 8809 = 6: 8(2) + 8(2) + 0(1) + 9(1) = 6 2222 = 0: 2(0) + 2(0) + 2(0) + 2(0) = 0 6855 = 3: 6(1) + 8(2) + 5(0) + 5(0) = 0 therefore, 2581 = 2: 2(0) + 5(0) + 8(2) + 1(0) = 2 2581 = 2

map 0, 6, and 9 to a value of ’1′
map 8 to a value of ’2′.
map any other digit to ’0′

sum up mapped digit values of the left number and you obtain the number on the right.

examples:

8809 = 6: 8(2) + 8(2) + 0(1) + 9(1) = 6
2222 = 0: 2(0) + 2(0) + 2(0) + 2(0) = 0
6855 = 3: 6(1) + 8(2) + 5(0) + 5(0) = 0

therefore,

2581 = 2: 2(0) + 5(0) + 8(2) + 1(0) = 2

]]> By: Stephen Downes http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50540 Stephen Downes Mon, 12 Jan 2009 00:35:10 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50540 2 2

]]> By: Sui Fai John Mak http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50539 Sui Fai John Mak Sun, 11 Jan 2009 23:39:45 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50539 The answer is 2. Here is the reason: The number of 2 is the 21 number If you subtract the 7th number (2) by 6th number (0)= 2 If you subtract the 14th number (5) by 13th number (3) = 2 If you subtract the 21st number (x)by 20th number (0), it should give you 2 I don't have a PhD yet. But I am passionate in Mathematics, and is interested in Game Theory in my Operational Research studies in my MSc. It still took me 5 minutes in working it out. I could see why it is difficult. Simply because people would like to share the problem, but how about the solution....that is outside the square! You are welcome to visit my blog http://suifaijohnmak.wordpress.com I could make up this mathematical problems if you like. John The answer is 2.
Here is the reason:
The number of 2 is the 21 number
If you subtract the 7th number (2) by 6th number (0)= 2
If you subtract the 14th number (5) by 13th number (3) = 2
If you subtract the 21st number (x)by 20th number (0), it should give you 2
I don’t have a PhD yet. But I am passionate in Mathematics, and is interested in Game Theory in my Operational Research studies in my MSc.
It still took me 5 minutes in working it out. I could see why it is difficult. Simply because people would like to share the problem, but how about the solution….that is outside the square!
You are welcome to visit my blog
http://suifaijohnmak.wordpress.com
I could make up this mathematical problems if you like.
John

]]> By: David http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50538 David Sun, 11 Jan 2009 13:56:34 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50538 2581 = 2 ? 2581 = 2 ?

]]> By: Mark Reid http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50537 Mark Reid Sun, 11 Jan 2009 07:44:21 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50537 @Michael Lugo 4444 = 4 or 0, depending on which font you use. @Michael Lugo

4444 = 4 or 0, depending on which font you use.

]]> By: Karthik http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50536 Karthik Sun, 11 Jan 2009 02:00:30 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50536 2581 = 2? 2581 = 2?

]]> By: Michael Lugo http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50535 Michael Lugo Sat, 10 Jan 2009 23:43:36 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50535 4444 = ? 4444 = ?

]]> By: phd student http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50534 phd student Sat, 10 Jan 2009 23:36:40 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50534 thanks God I don't have a phd yet, I was able to solve it thanks God I don’t have a phd yet, I was able to solve it

]]> By: Daniel Tunkelang http://lemire.me/blog/archives/2009/01/10/finish-this-sequence-of-equalities/comment-page-1/#comment-50533 Daniel Tunkelang Sat, 10 Jan 2009 23:24:03 +0000 http://www.daniel-lemire.com/blog/?p=1725#comment-50533 It's the opposite of an open problem. :-) It’s the opposite of an open problem. :-)

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