
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
 LinkBack  Thread Tools  Display Modes 
September 7th, 2019, 12:34 PM  #1 
Senior Member Joined: Dec 2015 From: somewhere Posts: 642 Thanks: 91  Equation with natural variable
$\displaystyle \lfloor n/1 \rfloor + \lfloor n/2 \rfloor +...+\lfloor n/(n1) \rfloor =7\; $, nnatural . To write it better : $\displaystyle \sum_{j=1}^{n1} \displaystyle \lfloor \frac{n}{j} \displaystyle \rfloor =7 \; $ ; n=? , Method Required ! Last edited by idontknow; September 7th, 2019 at 12:38 PM. 
September 8th, 2019, 02:27 AM  #2 
Senior Member Joined: Dec 2015 From: somewhere Posts: 642 Thanks: 91 
$\displaystyle m_1 =\lfloor 7/2 \lfloor $ and $\displaystyle m_{2} =1+m_1 $. $\displaystyle M=\frac{1+2m_1 }{2}=3,5$. Number of elements is $\displaystyle \lfloor 3,5 \rfloor =3 $ which is n+1 .So $\displaystyle n=4$. To verify : [4]+[4/2]+[4/3] =4+2+1=7 . 

Tags 
equation, natural, variable 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Two Natural Variables Equation  idontknow  Number Theory  8  January 28th, 2017 03:24 AM 
two variable equation  mhhojati  Linear Algebra  3  January 20th, 2017 04:41 AM 
simultaneous equation with a natural log  Silly Moo  Calculus  1  March 2nd, 2015 02:38 PM 
Natural Logarithm equation  BrianMX34  Algebra  5  September 8th, 2012 08:04 AM 
Help Solve this Natural Log Equation  Zaeem  Algebra  2  January 11th, 2011 03:39 AM 