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.)
A similar problem but perhaps a bit trickier | Comment 12 of 39 |
I'm new here, so please forgive me for posting this if I'm not supposed to, but I like this kind of problem. The technique to the problem is handy to remember in maths challenges...
The problem is this:

A student realises that a certain 12-digit number is exactly divisible by 11. His mate comes along and drops ink over the 8th digit. The student can now only read 11 of the 12 digits and cannot remember what the "inked" digit was. Can you work it out? The number now reads:
5643879x2841. (Where 'x' is the number blotted out with ink)

  Posted by Kirk on 2003-11-20 14:53:01
Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (1)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information