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

Home > General
Decimal Digits (Posted on 2014-09-02) Difficulty: 2 of 5

With respect to the decimal digits 0-9:

a) What is unique about 2?

b) What is common with 4, 5, and 6?

See The Solution Submitted by Bractals    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Trying yo guess... | Comment 4 of 5 |

The problem is interesting, but being vague, numerous solutions seem possible:

a1: 2 is the smallest prime

a2: 2 is the only even prime.

a3: 2 is the only even number equal to its factorial.

b1: this is the only triplet of a square, a prime and a triangular number in a consecutive sequence

b2:   this is the only triplet of digits in sequence  in which the middle number's factorial is equal to the product of all the members

b3: this is the only triplet of a square, a prime and a perfect number in a consecutive sequence.


Let's wait and compare with the official solution

???  How is it possible to edit a typo in my comment's title?

Edited on September 2, 2014, 8:18 pm
  Posted by Ady TZIDON on 2014-09-02 20:15:23

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