My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
February 25th, 2010, 04:04 AM   #1
Senior Member
 
Joined: Oct 2009

Posts: 895
Thanks: 1

2 question in permutations and Combination

1 ) There are 10 teams in a league. If each team is to play every other team exactly once,
A ) How many games must be scheduled?
B ) How many games must be on each team?


[color=#BF0000]
A ) 10C9 = 10

B ) 10C1 = 10[/color]


2 )_A catering service offers 8 appetizers, 10 main courses and 7 desserts. A Chairperson is to select
3 appetizers, 4 main courses and 2 desserts for A dinner. How many way can this be done?



[color=#BF0000]Here in this question we use C or P and why?[/color]
r-soy is offline  
 
February 25th, 2010, 12:20 PM   #2
Global Moderator
 
Joined: May 2007

Posts: 6,528
Thanks: 589

Re: 2 question in permutations and Combination

Your first question answers look completely wrong. A) is 45 and B) is 9.
mathman is offline  
February 26th, 2010, 03:54 AM   #3
Member
 
Joined: Feb 2010

Posts: 51
Thanks: 0

Re: 2 question in permutations and Combination

Quote:
Originally Posted by mathman
Your first question answers look completely wrong. A) is 45 and B) is 9.
mathman is right ( in fact he seldom be wrong, lol)

answer for 1A is 10C2 = 45
There are 10 teams and in each match, there will be 2 teams playing with each other.
The reason to choose 'C' but NOT 'P' is because the order is not important. For example, Team A playing with Team B is just the same as Team B playing with Team A.
When we use 'P', the order is important, for example,the arrangement of AB is not the same as BA.

For part b, since the question states that 'There are 10 teams in a league. If each team is to play every other team exactly once', that already shows that there are 9 matches each team is going to play (**Team A can't play with Team A in a competition, right?)

Well, I don't know whether it is the correct explanation because I just learnt it last month and that's just the way my maths teacher taught us. Hope that it helps
tomorrow is offline  
March 4th, 2010, 08:19 AM   #4
Newbie
 
Joined: Mar 2010

Posts: 2
Thanks: 0

Re: 2 question in permutations and Combination

2 more que's....

Q1) Calculate the number of ways in which the letters of the word TRIANGLES can be arranged if no two vowels may come together.

Q2) How many 7-digit numbers can be formed from the digits 0,1,2,2,3,3,3 assuming that a number can't start with 0 ?????????
maria1 is offline  
March 4th, 2010, 09:08 AM   #5
Global Moderator
 
Joined: Dec 2006

Posts: 19,065
Thanks: 1621

Hi maria1
Please create a new topic for your question instead of adding it to an existing topic.
skipjack is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
combination, permutations, question



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question About 180 Combinations/Permutations EvanJ Advanced Statistics 1 February 17th, 2014 05:09 PM
probability/permutations question jasonbing Advanced Statistics 1 December 13th, 2011 07:42 PM
H can't know the question ask about permutations or Combina r-soy Algebra 1 March 4th, 2010 02:35 AM
Awkward Permutations question david79 Applied Math 3 September 26th, 2009 05:17 PM
Permutations Question EternalSummer247 Advanced Statistics 2 August 17th, 2007 05:03 PM





Copyright © 2018 My Math Forum. All rights reserved.