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

Home > Just Math
50 - Digit Number (Posted on 2003-11-15) Difficulty: 3 of 5
A number of 50 digits has all its digits equal to 1 except the 26th digit. If the number is divisible by 13, then find the digit in the 26th place.

See The Solution Submitted by Ravi Raja    
Rating: 3.3333 (6 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
first thoughts | Comment 1 of 39
doubt this will help but the sum of the digits of multiples of thirteen (and the sum of those digits if their 2 digit numbers) goes in a patern:
4,8,3,7,2,4,1,5,9. Therefore, sice 3 and 6 arent present in the patern, we can rule out 2 and 8.
49*1+2=51. 5+1=6.
49*1+8=57. 5+7=12. 1+2=3.

  Posted by rerun141 on 2003-11-15 11:06:34
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