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

Home > Just Math
Tenacious Divisibility Treat (Posted on 2016-04-06) Difficulty: 2 of 5
A positive integer less than 30 million is such that if we subtract 5 from it – the resulting number is divisible by 8.

At the first step, from the number (considered originally) diminished by 5 - we subtract the eighth part. We then obtain a number that also becomes divisible by 8 after 5 is subtracted from it.

At the second step, we derive another in the same way, namely by subtracting a eighth part from the number at the end of the first step diminished by 5. The resulting number is also divisible by 8 after subtracting 5.

The operation concludes at 8th step given that at the end of 7th step we get a number that is divisible by 8 after after subtracting 5.

Determine the positive integer initially before the first step.

*** The resulting number at the end of 8th step is NOT necessarily divisible by 8 after subtracting 5.

  Submitted by K Sengupta    
Rating: 5.0000 (1 votes)
Solution: (Hide)
The positive integer initially before the first step was 16777181.

For an explanation, refer to the solution submitted by Brian Smith in this location.

Comments: ( You must be logged in to post comments.)
  Subject Author Date
SolutionSolutionLarry2023-11-06 10:07:52
Some Thoughtsre: broll's interpretation is correctAdy TZIDON2016-04-07 12:39:14
broll's interpretation is correctCharlie2016-04-07 10:41:07
Solutionre(2): Help from a negative (solution)....WRONGAdy TZIDON2016-04-07 09:10:48
Solutionre: Help from a negative (solution)broll2016-04-07 06:14:49
Hints/Tipsre: Help from a negative (solution)Ady TZIDON2016-04-06 12:54:42
Solutionmy numbersAdy TZIDON2016-04-06 12:25:44
SolutionHelp from a negative (solution)Brian Smith2016-04-06 10:30:14
solutionCharlie2016-04-06 10:14:35
Some ThoughtsNot surebroll2016-04-06 09:37:19
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 (3)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information