O'Reilly Forums: Pg 253 Questions About Permutations/ Combos - O'Reilly Forums

Jump to content

Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic

Pg 253 Questions About Permutations/ Combos Arranging individuls by type

#1 User is offline   AShiraz 

  • Active Member
  • PipPip
  • Group: Members
  • Posts: 12
  • Joined: 06-August 09

Posted 06 August 2009 - 03:54 PM

I noticed that for 251-253 about horses and zebras the winners can be :


HHH
HHZ
HZH
ZHH
ZHZ
ZZH
HZZ
ZZZ

That is eight different ways? Am I understanding the question incorrectly?
0

#2 User is offline   jr.larsen 

  • Active Member
  • PipPip
  • Group: Members
  • Posts: 26
  • Joined: 01-August 09

Posted 06 August 2009 - 05:13 PM

Yes, you have misunderstood.

The question is looking at the order all 6 animals finish in. So you could have
HHHZZZ
HHZHZZ
HHZZHZ
HHZZZH

HZHHZZ
HZHZHZ
HZHZZH

HZZHHZ
HZZHZH

HZZZHH

That's all the ways with a Horse first. By symmetry, there will also be 10 ways with a Zebra first.

So, there are 20 ways the 6 animals can finish the race, if we are not interested in individuals.

0

#3 User is offline   AShiraz 

  • Active Member
  • PipPip
  • Group: Members
  • Posts: 12
  • Joined: 06-August 09

Posted 11 August 2009 - 04:37 PM

Thanks that helps a lot!

QUOTE (jr.larsen @ Aug 6 2009, 05:13 PM) <{POST_SNAPBACK}>
Yes, you have misunderstood.

The question is looking at the order all 6 animals finish in. So you could have
HHHZZZ
HHZHZZ
HHZZHZ
HHZZZH

HZHHZZ
HZHZHZ
HZHZZH

HZZHHZ
HZZHZH

HZZZHH

That's all the ways with a Horse first. By symmetry, there will also be 10 ways with a Zebra first.

So, there are 20 ways the 6 animals can finish the race, if we are not interested in individuals.


0

Share this topic:


Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic

1 User(s) are reading this topic
0 members, 1 guests, 0 anonymous users