My Math Forum  

Go Back   My Math Forum > College Math Forum > Number Theory

Number Theory Number Theory Math Forum


Thanks Tree2Thanks
  • 1 Post By mathman
  • 1 Post By romsek
Reply
 
LinkBack Thread Tools Display Modes
August 6th, 2019, 01:10 PM   #1
Senior Member
 
Joined: Dec 2015
From: somewhere

Posts: 592
Thanks: 87

Prove division

Prove that $\displaystyle 40m \: | \: (5m)! \; $ , $\displaystyle m\in \mathbb{N}.$
idontknow is offline  
 
August 6th, 2019, 01:46 PM   #2
Global Moderator
 
Joined: May 2007

Posts: 6,806
Thanks: 716

Among the factors in 5m! are 5m, 4m, and 2m, which multiplied together is 40m$^3$, which is divisible by 40m.
Thanks from topsquark
mathman is offline  
August 6th, 2019, 01:50 PM   #3
Senior Member
 
romsek's Avatar
 
Joined: Sep 2015
From: USA

Posts: 2,529
Thanks: 1389

$(5m)! = 5m \cdot \dfrac{(5m-1)!}{8!} \cdot 8 \cdot 7! = 40m \cdot
\dfrac{(5m-1)!}{8}$
Thanks from topsquark
romsek is online now  
Reply

  My Math Forum > College Math Forum > Number Theory

Tags
division, prove



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Long Division and Synthetic Division DarkPassenger Algebra 1 June 22nd, 2015 12:07 AM
Division Mr Davis 97 Elementary Math 3 May 9th, 2014 10:12 AM
If revenue's at the Zurich division were less than those at Prague Division, then Zur pnf123 Advanced Statistics 0 March 29th, 2014 05:26 AM
prove prove prove. currently dont know where to post qweiop90 Algebra 1 July 31st, 2008 06:27 AM
prove prove prove. currently dont know where to post qweiop90 New Users 1 December 31st, 1969 04:00 PM





Copyright © 2019 My Math Forum. All rights reserved.