My Math Forum  

Go Back   My Math Forum > Welcome > New Users

New Users Post up here and introduce yourself!


Thanks Tree2Thanks
  • 2 Post By skipjack
Reply
 
LinkBack Thread Tools Display Modes
March 31st, 2019, 10:45 AM   #1
Newbie
 
Joined: Mar 2019
From: N.Ireland

Posts: 5
Thanks: 0

Impossible thought

3 x 4 = 12... 7 x 8 = 56...
Nb the sequence of digits...
Is there any other combination of consecutive digits that produce an answer which itself is made up from consecutive digits...
In these examples the answer is also the immediate precursors to the sequence of the multipliers ...coincidence??

Of course .... Is there a simple proof showing these are the only numbers ?
Paulb is offline  
 
March 31st, 2019, 11:03 AM   #2
Senior Member
 
Joined: Aug 2012

Posts: 2,343
Thanks: 732

9 x 10 = 90.
Maschke is offline  
March 31st, 2019, 11:05 AM   #3
Newbie
 
Joined: Mar 2019
From: N.Ireland

Posts: 5
Thanks: 0

Vg... Nicely done... With some poetic licence
Paulb is offline  
March 31st, 2019, 11:51 AM   #4
Newbie
 
Joined: Mar 2019
From: N.Ireland

Posts: 5
Thanks: 0

Doh.... Forgot to say excluding 1 x ( n, n+ 1,n+2 ,n+3 ....... )

Last edited by Paulb; March 31st, 2019 at 12:22 PM.
Paulb is offline  
March 31st, 2019, 12:20 PM   #5
Global Moderator
 
Joined: Dec 2006

Posts: 20,835
Thanks: 2162

78 × 79 = 6162
skipjack is offline  
March 31st, 2019, 12:23 PM   #6
Newbie
 
Joined: Mar 2019
From: N.Ireland

Posts: 5
Thanks: 0

Yes many answers with nice figures but not sequential...
Paulb is offline  
March 31st, 2019, 12:49 PM   #7
Global Moderator
 
Joined: Dec 2006

Posts: 20,835
Thanks: 2162

Poetic licence allows me to use a number base of 100 instead of 10.

As you didn't require the consecutive digits to be in ascending order, 7 × 6 × 5 = 210.
Thanks from topsquark and Paulb
skipjack is offline  
March 31st, 2019, 12:55 PM   #8
Newbie
 
Joined: Mar 2019
From: N.Ireland

Posts: 5
Thanks: 0

Brilliant......
Paulb is offline  
Reply

  My Math Forum > Welcome > New Users

Tags
impossible, thought



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Not every thought ... johnr New Users 12 May 15th, 2013 03:07 PM
A thought... (regarding primes) Mark Number Theory 6 October 22nd, 2007 04:17 PM





Copyright © 2019 My Math Forum. All rights reserved.