Quandaries and Queries
 

 

Hi there! My name is Cheryl.  I would like to know the total possible combinations using the numbers 1-12. We would also like to know the formula used to calculate the number of combinations.

 

 

Hi Cheryl,

I am not quite sure what you are looking for. If you had asked for the number of combinations of, for example, 4 numbers taken from 1-12 then I would know what they are. They are four number strings like 2,4,6,3; and 12,5,3,8. Is this what you are looking for? Can you be more explicit?

Harley

 

Good Morning Harley,
 
We want to know how many possible combinations there would be using 1,2,3,4,5,6,7,8,9,10,11,12 without using the same number twice, but using all the numbers.
 
Cheryl

 

Hi Cheryl,

Penny answered a very similar question yesterday. It was about letters rather than numbers, and six of them rather than 12, but the idea is the same. You should look at Penny's answer. In your case, with 12 numbers, the number is 12x11x10x...x2x1=479001600. This number is called "twelve factorial" and written 12!, so, for example 4!=4x3x2x1=24.

These 479001600 "strings" of the 12 numbers, for example 1,2,3,4,5,6,7,8,9,10,11,12 and 2,4,6,8,10,12,11,9,7,5,3,1, mathematicians call permutations of the 12 numbers rather than combinations. This comes from a 19th century use of the English word combination which mathematicians insist on still using, even though it does not agree with the current dictionary meaning of combination. Hence my confusion with the original wording of your question.

I hope this answers your question.

Harley

 
 

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