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Browse High School Permutations/Combinations
Stars indicate particularly interesting answers or
good places to begin browsing.
 Choose Three People from Five [05/09/2001]

What do the fractions in the numerator and denominator mean? Where does
the formula come from?
 Choosing Computer Disks [12/01/2001]

A bin of computer disks contains a supply of disks from four different
manufacturers. In how many ways can you choose 6 disks from the bin?
 Combinations of Images on a TV Screen [12/6/1995]

I'd like to know how many images would be possible on a hypothetical TV
screen.
 Combinations of the Letters in a Name [03/04/1998]

A formula for the number of combinations of the letters in a name,
however many times one letter appears in that name.
 Combinatorics Basics [07/07/1997]

I need to prove that n chooses n1 = n; e.g. C(n,n1) = n.
 Committee of Six [10/07/1999]

A club has 8 male and 8 female members and is choosing a committee of 6
members, 3 male and 3 female. How many different committees can be
chosen?
 Counting Answer Keys [05/25/2001]

A multiplechoice test has 30 questions, each with five choices. How many
answer keys are possible?
 From RockPaperScissors to Stars and Bars [06/17/2014]

An adult struggles to calculate multiplayer Roshambo outcomes without explicitly
enumerating clenched fists, open palms, and two fingers. Doctor Ian explains why
neither permutations nor combinations applies to such a scenario of replacement
without regard to order; Doctor Peterson introduces a new approach.
 Handshakes and Polygon Diagonals [09/12/2001]

If a polygon has 42 sides, how many diagonals does it have?
 Math Symbol for C [12/15/1997]

I am puzzled by one symbol of typing math. What does the upper case
letter C mean? As in (2C1) (3C1) / (47C2) = 6/1081.
 Number and Letter Combinations [07/29/1997]

How many possible combinations can a person make with the letters az and
19 starting from 1 digit and ending up with up to 8 digits?
 Number of Combinations for 7 Dice [2/22/1995]

I'm looking for the derived formula solution for the following problem
someone posted in a math echo: There are seven dice. Each die has six
faces. How many different combinations are there of these seven dice?
 Number of Possible Telephone Numbers [7/15/1996]

How many phone numbers are there given the following restrictions on
certain digits of the number....?
 Number of Squares in an NxN Square [7/29/1996]

How many squares are there in an 8 x 8 square? How many rectangles are
there?
 Odds vs. Probability [12/06/1996]

What's the probability that a man can draw the numbers 2 and 7 from a hat
containing the numbers 18?
 Pascal's Triangle and Binomial Coefficients [09/11/2001]

Why are Pascal's triangle and the binomial coefficients the same?
 Pascal's Triangle and the Tower of Hanoi [08/07/1997]

There's a connection between Pascal's Triangle and the Tower of Hanoi
game but I can't remember what it is!
 Permutations and Combinations: Deriving Formulae [06/18/1998]

I have been trying to figure out how to arrive at the formula for
calculating combinations.
 Possible Letter Arrangements [07/05/2000]

Is there a formula I can use to quickly get the number of possible
arrangements of five, six,or seven different letters?
 Powerball Lottery: Odds of Winning a Prize [09/02/2001]

How are the Powerball lottery odds established?
 Rank of the Word FOCUS [06/27/2003]

The letters 'CFOSU' are arranged in dictionary order. What is the
rank of the word 'FOCUS' in this order?
 Round Robin Tournament Schedule [03/31/2000]

Is there a systematic way to come up with a schedule for a round robin
tournament for up to 32 teams, where each team plays every other team
once?
 Squares in Rectangle Formula [06/30/2003]

What is the equation for the number of squares in a rectangle (like
the chessboard puzzle)?
 Ways To List 1, 2, ... 10 Out of Order [02/25/1997]

How many ways are there to list the numbers one through ten so that no
number appears in its own position (i.e. 1 is not first in the list, 2 is
not second...)?
 20 Golf Players [04/11/1997]

How do you set up four teams such that the variance in the average team
handicap is no more than one or two?
 Algorithm for Derangements [01/11/2003]

I have been looking for a recursive algorithm to find all possible
derangements of a set n.
 Analyzing Prime Factors [06/14/2007]

Is there a number that has only three prime divisors (3, 5, and 7) and
that has a total of 18 divisors?
 Arrangement [07/12/1999]

How can I reduce the number of arrangements of the word ARRANGEMENT by
using the probability of an occurrence?
 Arrangements of 0's, 1's, and 2's [03/14/2002]

How many arrangements of six 0's, five 1's, and four 2's are there in
which i) the first 0 precedes the first 1? ii) the first 0 precedes the
first 1, precedes the first 2?
 Arrangements of Letters [09/14/1999]

In how many ways can the letters in UNUNSUAL be arranged? For those
arrangements, how many have all 3 U's together?
 Arranging Letters [11/08/1998]

In how many ways can the letters in MISSISSIPPI be arranged? Suppose the
2 P's must be separated?... and other such problems.
 Arranging Marbles in Boxes [09/16/1998]

Six marbles are placed in one of three different boxes. What is the
probability that each box contains two marbles?
 Arranging Things on a Shelf [05/05/2006]

Lucy has four vasesblue, yellow, red, and purple. How many ways can
she arrange her vases in a row on a shelf?
 Balls in Boxes [05/05/1999]

You have 2*t + 1 balls to put into 3 boxes, but the sum of the balls in 2
of the boxes should be more then the balls in the other box...
 Baseball Batting Orders [10/14/2001]

How many possible batting orders are there for a team of nine players?
 Beads on a Bracelet [05/04/1997]

How many different arrangements of 3 red and 3 blue beads on a bracelet
are there?
 Bell Number [02/24/2002]

I am trying to figure out how many different groups 50 people can be
partitioned into.
 Bell Numbers [08/29/2001]

I am looking for the formula for the number of different groups we can
split a group of n different items into  order does not matter.
 Binomial Probability [04/14/1999]

A multiplechoice exam probability question.
 Blocks of Seats [11/08/1998]

In a row of 20 seats, in how many ways can 3 blocks of consecutive seats
with 5 seats in each block be selected? And more such problems...
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