April 9th, 2017, 08:31 PM  #1 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory  Unique digital fractions sum to one
What equation ab/cd+efg/hij=1 is unique since it expresses "1" as sum of two fractions using all the digits from 0 to 9 exactly once each. Hint: both addends equal 1/2. 
April 9th, 2017, 09:55 PM  #2 
Senior Member Joined: Sep 2015 From: USA Posts: 1,979 Thanks: 1027 
there seem to be quite a lot of solutions to this (over 14,000 before I stopped it)

April 9th, 2017, 10:19 PM  #3 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory 
Thanks to you, romsek, I now believe there is a considerable plurality of permutations  but over 14,000? I found the brainteaser online. 
April 9th, 2017, 10:27 PM  #4  
Senior Member Joined: Sep 2015 From: USA Posts: 1,979 Thanks: 1027  Quote:
Didn't even need that long. There are 15264 numbers that satisfy this. Incidentally in all of them either the first or second term is 1. (and the other 0) Last edited by romsek; April 9th, 2017 at 10:41 PM.  
April 9th, 2017, 10:34 PM  #5 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory 
I'll sleep on it 
April 10th, 2017, 01:53 AM  #6 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory 
My question required that each term equal 1/2.

April 10th, 2017, 03:20 AM  #7 
Global Moderator Joined: Dec 2006 Posts: 19,059 Thanks: 1619 
For the equation's intended interpretation, 35/70 + 148/296 = 1.

April 10th, 2017, 08:52 AM  #8 
Senior Member Joined: Sep 2015 From: USA Posts: 1,979 Thanks: 1027  
April 10th, 2017, 12:47 PM  #9 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory 
Let me ask that the 'hint' I gave rather be a 'requirement' of a problem: "Each addend must equal 1/2." __________ I have found that in mathematics, writing the problem is often over half of solving it. I am sorry if I wasted your time. 
April 10th, 2017, 12:49 PM  #10 
Senior Member Joined: May 2015 From: Arlington, VA Posts: 361 Thanks: 26 Math Focus: Number theory 
skipjack found the correct solution given by my source.


Tags 
digital, fractions, sum, unique 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
digital handwriting pad recommendation  blimper  Math Software  5  January 29th, 2017 04:05 AM 
digital roots  mathfailer96  Number Theory  1  August 10th, 2014 09:48 AM 
Digital Signal Processing  hexadecimal  Academic Guidance  2  January 29th, 2013 10:16 AM 
Digital Root Question  Mysty  Number Theory  0  April 18th, 2010 12:33 PM 
Digital Signal Processing  hexadecimal  Algebra  0  December 31st, 1969 04:00 PM 