
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
 LinkBack  Thread Tools  Display Modes 
April 27th, 2018, 02:22 AM  #1 
Senior Member Joined: Aug 2014 From: India Posts: 332 Thanks: 1  How to understand this solution?
In how many ways can a team of four be selected from eight players? 1) When one player is always included? 2) When one player is always excluded? Solution: 1) Since one player is always included, then we have to select three players from seven which can be done in 7C3 ways. 2) Since one player is always excluded then we have to select 4 players from 7 which can be done in 7C4 ways. My question: why in both cases 7 is taken instead of 8? I mean 7C3 and 7C4 etc. 
April 27th, 2018, 04:07 AM  #2 
Math Team Joined: Jan 2015 From: Alabama Posts: 3,261 Thanks: 894 
In the first problem "one player is always included" so we select the remaining 3 players from the other 7. In the second problem "one play is always excluded" so we can ignore him and choose all four players from the other 7. Last edited by skipjack; April 27th, 2018 at 06:44 AM. 
April 27th, 2018, 06:47 AM  #3 
Global Moderator Joined: Dec 2006 Posts: 19,742 Thanks: 1815 
The question is unclear anyway, as "team" isn't defined.


Tags 
solution, understand 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Don't understand the solution to the Questions. Please help  KaiL  Probability and Statistics  4  March 28th, 2016 05:19 AM 
Trigonometry  I don't understand the solution  Psyduck  Trigonometry  1  July 2nd, 2013 07:38 PM 
simple question, but can't understand the solution.....  mathmaniac  Advanced Statistics  17  February 25th, 2013 11:58 PM 
I dont understand why this log. equation has no solution  RealMadrid  Algebra  6  June 5th, 2012 06:34 AM 
trying to make a solution (liquid solution...) problem...  TreeTruffle  Algebra  2  March 27th, 2010 01:22 AM 