All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Reverse Role (Posted on 2014-10-15) Difficulty: 3 of 5
A two-digit base 7 positive integer has its digits reversed when expressed in base N.

What are the possible values of N satisfying the given conditions?

No Solution Yet Submitted by K Sengupta    
Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution sollution | Comment 1 of 4

let b be the base:

7x+y=b*y+x

6x=(b-1)*y     eq1

base 3:   12 b7  is 21 ternary

base 5:   23 b7  is  32  b5

 base 10:   32 b7  is  23  b10    and  64 b7  is   46  b10

base 13:   21==>12;   42==>24;    63==>36; 

base 16:  52==>25; 
base 19:  31==>13;   62==>26;

highr bases may comply with the equation eq1, but introduce digits higher than 6.

So se are left with bases 3,5,10,13,16,19


  Posted by Ady TZIDON on 2014-10-15 11:44:41
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information