Coombinatorics- The number of ways of choosing with parametersDifferent ways of coloring a $4 times 4$ game...
Why is it that Bernie Sanders is always called a "socialist"?
Possible issue with my W4 and tax return
How long has this character been impersonating a Starfleet Officer?
Where does documentation like business and software requirement spec docs fit in an agile project?
Is the fingering of thirds flexible or do I have to follow the rules?
How do I avoid the "chosen hero" feeling?
Minimum Viable Product for RTS game?
Why do single electrical receptacles exist?
Is it really OK to use "because of"?
Computing Cardinality of Sumsets using Convolutions and FFT
Why does alert(0.-5) print -5?
How do you get out of your own psychology to write characters?
Coombinatorics- The number of ways of choosing with parameters
Word for something that's always reliable, but never the best?
Why do neural networks need so many examples to perform?
Why did Ylvis use "go" instead of "say" in phrases like "Dog goes 'woof'"?
Is .NET Framework 3.5 still needed with a SQL Server 2017 installation to utilize Database Mail?
How to align the top of the text with the top of a figure produced by tikz in minipage
Renting a 2CV in France
RS485 using USART or UART port on STM32
What does an unprocessed RAW file look like?
Rigorous justification for non-relativistic QM perturbation theory assumptions?
What is a good reason for every spaceship to carry gun on board?
How to politely refuse in-office gym instructor for steroids and protein
Coombinatorics- The number of ways of choosing with parameters
Different ways of coloring a $4 times 4$ game boardWhat does the “n choose multiple numbers” symbol stands for?Recurrence Relation, Discrete Math problem(Homework)Condition over CombinationsWith how many different ways can Adriana be dressed…????Counting the number of trials.Number of ways to pick balls with conditions on their colorsIn how many ways we can color $15$ eggs..In how many ways can two different colored balls be chosen?Combinatorics: Coloring a prism
$begingroup$
Here's the problem:
At our disposal is a collection of 10 red, 11 blue and 12 yellow fabrics. (each fabric is unique)In how many ways can we choose 4 different fabrics if we want at least one fabric of each of the three colors?
My solution was since the first fabric chosen must be red, there are 10 options for it. Then the next fabric must be blue, which has 11 options. The third fabric is yellow, with 12 options, and the last fabric can be any of the colors, provided that it has not already been chosen, so there are (9+10+11-3)= 30 ways to choose the last one, making the total number of choices 9*10*11*30.
My professor said that I needed to divide that by 2 to get the right answer, but I just don't understand why. Any help would be much appreciated!
combinatorics discrete-mathematics
New contributor
$endgroup$
add a comment |
$begingroup$
Here's the problem:
At our disposal is a collection of 10 red, 11 blue and 12 yellow fabrics. (each fabric is unique)In how many ways can we choose 4 different fabrics if we want at least one fabric of each of the three colors?
My solution was since the first fabric chosen must be red, there are 10 options for it. Then the next fabric must be blue, which has 11 options. The third fabric is yellow, with 12 options, and the last fabric can be any of the colors, provided that it has not already been chosen, so there are (9+10+11-3)= 30 ways to choose the last one, making the total number of choices 9*10*11*30.
My professor said that I needed to divide that by 2 to get the right answer, but I just don't understand why. Any help would be much appreciated!
combinatorics discrete-mathematics
New contributor
$endgroup$
add a comment |
$begingroup$
Here's the problem:
At our disposal is a collection of 10 red, 11 blue and 12 yellow fabrics. (each fabric is unique)In how many ways can we choose 4 different fabrics if we want at least one fabric of each of the three colors?
My solution was since the first fabric chosen must be red, there are 10 options for it. Then the next fabric must be blue, which has 11 options. The third fabric is yellow, with 12 options, and the last fabric can be any of the colors, provided that it has not already been chosen, so there are (9+10+11-3)= 30 ways to choose the last one, making the total number of choices 9*10*11*30.
My professor said that I needed to divide that by 2 to get the right answer, but I just don't understand why. Any help would be much appreciated!
combinatorics discrete-mathematics
New contributor
$endgroup$
Here's the problem:
At our disposal is a collection of 10 red, 11 blue and 12 yellow fabrics. (each fabric is unique)In how many ways can we choose 4 different fabrics if we want at least one fabric of each of the three colors?
My solution was since the first fabric chosen must be red, there are 10 options for it. Then the next fabric must be blue, which has 11 options. The third fabric is yellow, with 12 options, and the last fabric can be any of the colors, provided that it has not already been chosen, so there are (9+10+11-3)= 30 ways to choose the last one, making the total number of choices 9*10*11*30.
My professor said that I needed to divide that by 2 to get the right answer, but I just don't understand why. Any help would be much appreciated!
combinatorics discrete-mathematics
combinatorics discrete-mathematics
New contributor
New contributor
New contributor
asked 4 hours ago
cmplxlizcmplxliz
111
111
New contributor
New contributor
add a comment |
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Because under your scheme you would count, for example, both
$$R1,B1,Y1,R2quadhbox{and}quad R2,B1,Y1,R1 .$$
But these are actually the same choice and therefore should not be counted twice.
$endgroup$
add a comment |
$begingroup$
The total number of ways is $binom {10} {2} binom {11} {1} binom {12} {1} + binom {10} {1} binom {11} {2} binom {12} {1} + binom {10} {1} binom {11} {1} binom {12} {2} = 19800.$
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
cmplxliz is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3125635%2fcoombinatorics-the-number-of-ways-of-choosing-with-parameters%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Because under your scheme you would count, for example, both
$$R1,B1,Y1,R2quadhbox{and}quad R2,B1,Y1,R1 .$$
But these are actually the same choice and therefore should not be counted twice.
$endgroup$
add a comment |
$begingroup$
Because under your scheme you would count, for example, both
$$R1,B1,Y1,R2quadhbox{and}quad R2,B1,Y1,R1 .$$
But these are actually the same choice and therefore should not be counted twice.
$endgroup$
add a comment |
$begingroup$
Because under your scheme you would count, for example, both
$$R1,B1,Y1,R2quadhbox{and}quad R2,B1,Y1,R1 .$$
But these are actually the same choice and therefore should not be counted twice.
$endgroup$
Because under your scheme you would count, for example, both
$$R1,B1,Y1,R2quadhbox{and}quad R2,B1,Y1,R1 .$$
But these are actually the same choice and therefore should not be counted twice.
answered 4 hours ago
DavidDavid
69.2k667130
69.2k667130
add a comment |
add a comment |
$begingroup$
The total number of ways is $binom {10} {2} binom {11} {1} binom {12} {1} + binom {10} {1} binom {11} {2} binom {12} {1} + binom {10} {1} binom {11} {1} binom {12} {2} = 19800.$
$endgroup$
add a comment |
$begingroup$
The total number of ways is $binom {10} {2} binom {11} {1} binom {12} {1} + binom {10} {1} binom {11} {2} binom {12} {1} + binom {10} {1} binom {11} {1} binom {12} {2} = 19800.$
$endgroup$
add a comment |
$begingroup$
The total number of ways is $binom {10} {2} binom {11} {1} binom {12} {1} + binom {10} {1} binom {11} {2} binom {12} {1} + binom {10} {1} binom {11} {1} binom {12} {2} = 19800.$
$endgroup$
The total number of ways is $binom {10} {2} binom {11} {1} binom {12} {1} + binom {10} {1} binom {11} {2} binom {12} {1} + binom {10} {1} binom {11} {1} binom {12} {2} = 19800.$
answered 3 hours ago
Dbchatto67Dbchatto67
1,134118
1,134118
add a comment |
add a comment |
cmplxliz is a new contributor. Be nice, and check out our Code of Conduct.
cmplxliz is a new contributor. Be nice, and check out our Code of Conduct.
cmplxliz is a new contributor. Be nice, and check out our Code of Conduct.
cmplxliz is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3125635%2fcoombinatorics-the-number-of-ways-of-choosing-with-parameters%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown