Math Is Fun Forum

jackson6612

Member

Registered: 2006-07-19

Posts: 5

the forumula 2^n to find distinct values

Hi

What is this formula called 2^n which is used to find number of distinct combinations? Does this have anything to with permutation? Please help me with this. Thanks.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,583

Re: the forumula 2^n to find distinct values

hi jackson6612,

This sounds a bit like how many different ways can a set  of n coins come down if order matters.

eg HTHHTHHHTH; HHHHHHHHHH; HHHHHHHTTT etc.  In this case n = 10 and there 1024 different orderings of Hs and Ts.

It doesn't have to be coins either any binary situation would be the same

eg { EVEN ODD EVEN ODD ODD ODD } ; { ODD ODD ODD ODD ODD ODD } and so on.

As order matters it's a permutation problem rather than combination.

In my first example with coins and n = 10 there are only these possiblities if order doesn't matter

10H; 9H1T; 8H2T; 7H3T; 6H4T; 5H5T; 4H6T; 3H7T; 2H8T; 1H9T; 10T.

Is that what you were after?

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: the forumula 2^n to find distinct values

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. . . . . (Order does not matter.)

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