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Sep 4th, 2006, 03:19 AM
#1
Thread Starter
New Member
Permutations Quiz
Hi Everyone,
I'm new to the Forum so I thought I'd introduce myself wilh a little brain teaser.
OK, so,
you have 4 checkboxes,
each has 2 values, (1,0)
Only 1 value can be selected at a time (per checkbox)
How many Possible permutations of checkboxes are there ?
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Sep 4th, 2006, 06:40 AM
#2
Addicted Member
Re: Permutations Quiz
0,0,0,0 gives 1 possible
1,0,0,0 gives 4 possibles
1,1,0,0 gives 3 + 2 + 1 = 6 possibles
1,1,1,0 gives 4 possibles
1,1,1,1 gives 1 possible
1 + 4 + 6 + 4 + 1 = 16 possibles
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Sep 4th, 2006, 06:41 AM
#3
Member
Re: Permutations Quiz
 Originally Posted by zelwin
Hi Everyone,
I'm new to the Forum so I thought I'd introduce myself wilh a little brain teaser.
OK, so,
you have 4 checkboxes,
each has 2 values, (1,0)
Only 1 value can be selected at a time (per checkbox)
How many Possible permutations of checkboxes are there ? 
Been along time since i've done permutations but... uh...
Each checkbox has 2 values so the total combinations for 1 checkbox is 2.
There are 4 checkbox so it would be 2^4. I think.
That gives you 16 combinations. I may be wrong.
Someone beat me to it Oh well. At least it looks like I was right.
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Sep 4th, 2006, 08:16 AM
#4
Thread Starter
New Member
Re: Permutations Quiz
 Originally Posted by Glaysher
0,0,0,0 gives 1 possible
1,0,0,0 gives 4 possibles
1,1,0,0 gives 3 + 2 + 1 = 6 possibles
1,1,1,0 gives 4 possibles
1,1,1,1 gives 1 possible
1 + 4 + 6 + 4 + 1 = 16 possibles
I think you are on the right track but there is a third dimension,
1,0,0,0
1,1,0,0
1,1,1,0
1,1,1,1
0,1,0,0
0,1,1,0
0,1,1,1
0,0,1,0
0,0,1,1
0,0,0,1
ETC...
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Sep 4th, 2006, 08:22 AM
#5
Thread Starter
New Member
Re: Permutations Quiz
 Originally Posted by zelwin
I think you are on the right track but there is a third dimension,
1,0,0,0
1,1,0,0
1,1,1,0
1,1,1,1
0,1,0,0
0,1,1,0
0,1,1,1
0,0,1,0
0,0,1,1
0,0,0,1
ETC... I may be very wrong though.
This problem refers to 4 check boxes that i have to state wether an item has, or has not, got one of these features
yes=1
no=0
The items can have any combination of features. I am not so good at maths and having looked up how to calculate Permutations i was completely confused so i tried to work it out on paper.
Origionally i came up with 13 but then notised i had missed out 2 possible combinations so i now have 15
If you are right with 16 then I am pretty happy and very thankfull as it means i have only missed 1.
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Sep 4th, 2006, 09:02 AM
#6
Addicted Member
Re: Permutations Quiz
 Originally Posted by zelwin
I think you are on the right track but there is a third dimension,
1,0,0,0
1,1,0,0
1,1,1,0
1,1,1,1
0,1,0,0
0,1,1,0
0,1,1,1
0,0,1,0
0,0,1,1
0,0,0,1
ETC...
I have counted all those. I just didn't write out the different orders, just how many different orders exist for each possible combination of 0s and 1s
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Sep 4th, 2006, 09:04 AM
#7
Addicted Member
Re: Permutations Quiz
All possible
0,0,0,0
1,0,0,0
0,1,0,0
0,0,1,0
0,0,0,1
1,1,0,0
1,0,1,0
1,0,0,1
0,1,1,0
0,1,0,1
0,0,1,1
1,1,1,0
1,1,0,1
1,0,1,1
0,1,1,1
1,1,1,1
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Sep 5th, 2006, 08:58 AM
#8
Re: Permutations Quiz
 Originally Posted by zelwin
you have 4 checkboxes,
each has 2 values, (1,0)
Only 1 value can be selected at a time (per checkbox)
How many Possible permutations of checkboxes are there ? 
This is the same as generating all possible binary numbers with four digits, so 24.
Lottery is a tax on people who are bad at maths
If only mosquitoes sucked fat instead of blood...
To do is to be (Descartes). To be is to do (Sartre). To be do be do (Sinatra)
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Sep 5th, 2006, 01:29 PM
#9
Re: Permutations Quiz
Incidentally, be careful when using the word "permutations". This often implies that things can be swapped around, so 1,2 is different from 2,1. In your case, you are really looking for the number of combinations of these checkboxes.
4C0 + 4C1 + 4C2 + 4C3 + 4C4
=
1 + 4 + 6 + 4 + 1
=
16 as stated above.
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Sep 6th, 2006, 02:34 AM
#10
Thread Starter
New Member
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Sep 6th, 2006, 11:57 AM
#11
Addicted Member
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