# Questions tagged [permutations]

For questions related to permutations, which can be viewed as re-ordering a collection of objects.

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### How many different 5-letter strings are possible? [closed]

I'm assuming a 26-letter alphabet with 5 letters picked randomly. Repeats are allowed and order matters. How many possible permutations (if that's the right word)?
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### How many permutations are there of the letters of the word AARDVARK? In how many of the permutations are the A's separated?

How many permutations are there of the letters of the word AARDVARK? In how many of the permutations are the A's separated? I got answer for the first part of the question, but for the second part I ...
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### How do I represent hexagons (or any polygon really) so that they are equal independent of rotation?

I am working on a private coding project. My program works with hexagons, which edges have certain features. I currently represent these hexagons using arrays with one entry for each edge. There is a ...
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### The difference between permutation and composition in the subject of probability

In general we have: $$\dfrac{p(k,r)}{p(n,r)}=\dfrac{c(k,r)}{c(n,r)}$$ is it different or same in the topic of probability to solve the question by permutation or combination? For example, from 5 green ...
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### how many three letter permutations are there of the letters of the word EQUILATERAL [closed]

I tried 11P3/(2!x2!x2!) and then I tried (11!/(2!x2!x2!))/8! but always end up with a decimal number and I don't understand why this won't work.
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### Is a transitive group more likely to be soluble if its degree has more prime divisors?

There is some empirical evidence that the probability that a permutation group of a given degree is soluble increases with the number of prime divisors of the degree. (Primes are counted with ...
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### the number of ways to order a line from a group of 6 women and 2 men such that 2 men stand on either end?

Given a group of 6 women and 2 men, I have to find the number of ways in which atleast one man is on one end of the line. I tried to separate the cases where both men take the ends and when only one ...
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### Why can we not use combinations?

. A 3-person basketball team consists of a guard, a forward, and a centre. a) If a person is chosen at random from each of three different such teams, what is the probability of selecting a complete ...
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