|
Author
|
Message
|
![[Post New]](/templates/default/images/icon_minipost_new.gif)
11 Jan 2008 22:58:49 IST
|
|
|
This is easy. Total number of ways of selecting 7 people = 16c7 From this we have to subtract number of ways all three are consecutive =16 and also the number of ways inwhich two are consecutive = 16x 12c1 Therefore the final answer is = 16c7 - 16 - 16x12c1. Got it???
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
11 Jan 2008 23:06:35 IST
|
|
|
Somebody please rate me!!!
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
17 Jan 2008 13:45:56 IST
|
|
|
ffff
|
http://beverlys.net/LJ/BuggingYou.swf
www.agaaz.com |
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
27 Jan 2008 00:38:38 IST
|
|
|
to select 7 people such that none is consecutive would be
First person can occupy any of the 16 chairs
Second person can sit in rest of the 13 chairs
Third in 11, Fourth in 9,Fifth in 7, Sixth in 5 ,proceeding in this way
Therefore total number of ways to sit= 16*13*11*9*7*5*3=2162160
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
27 Jan 2008 00:43:50 IST
|
|
|
Ways to select 7 people such that none is consecutive would be
First person can occupy any of the 16 chairs
Second person can sit in rest of the 13 chairs
Third in 11, Fourth in 9,Fifth in 7, Sixth in 5 ,proceeding in this way
Therefore total number of ways to sit= 16*13*11*9*7*5*3=2162160
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
3 Feb 2008 19:26:26 IST
|
|
|
15! -5!*2!
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
9 Mar 2008 17:36:07 IST
|
|
|
My answer is same as the winner's answer but i 'll try to explain my method in a much simpler way.
consider the no. of gaps ( students) in between 2 chosen students. let them be x1, x2, .. x7.
total no. of such gaps = 16 - 7 =9
Therefore x1 + x2 + x3 + x4 + x5 + x6 +x7 = 9
the no. of solutions of this equation is ( 9-1 ) C ( 7 - 1) = 8C6
now the first person can be chosen in 16 ways. and it does not matter which of the 7 students in the final answer is the first student .
So the final answer is 16 8C6 / 7
|
this reply:
5 points
(with 1
in
1
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
30 Apr 2008 20:33:02 IST
|
|
|
IS THE ANSWER 56 ??????
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
31 May 2008 13:16:03 IST
|
|
|
|
let us consider the case of selecting a sign(+ve/-ve)
out of + - + - ....+ where total signs are 17.
but nou 17th sign(as it will become consicutive)
similarly we select people
therefore answer should be:
= 2 * 8c7
|
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
31 May 2008 13:54:21 IST
|
|
|
total arrangements(for 7) can be done is 16C7 and no consecutives so
so total no.of aarangements are 16C7-16C2
|
remember d earth!!!!letz clean the green.......letz spread this to all of us............. |
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
22 Jul 2008 16:18:25 IST
|
|
|
Re:Contest [swordfish #2]: Find ways to select people on circular table
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
9 Sep 2008 17:29:58 IST
|
|
|
select 7 from 16 ,and arrange them,
16-7 C 2 ,that is 9 C 2, i.e . 36 is th answer
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
21 Oct 2008 21:04:36 IST
|
|
|
5
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
11 Apr 2009 06:36:31 IST
|
|
|
(16c1* 8c6)/7==64
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
17 Apr 2011 23:31:29 IST
|
|
|
Contest [swordfish #2]: Find ways to select people on circular table
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
18 Apr 2011 08:25:10 IST
|
|
|
well number of ways of arranging 16 people in a circle is (16-1)! or 15!. so first person can be seated in any 16 seats the next can sit on any 13(since he should not be seated on either side of the first person), then the third can sit in any 11 seats ........ and so on. so total number of ways comes out to be 16*13*11*9*7*5*3 that is 2162160 answer.
|
this reply:
0 points
(with 0
in
0
votes
)
[?]
|
|
You have to be logged on to rate
|
|
|
|
|
Moderation Team
Community Discussion Question:
![[Up]](/templates/default/images/icon_up.gif "[Up]"){kind=icon}
