How many ways letters be placed so at least two of them are in wrong envelopes? [duplicate]

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
-1
down vote

favorite













This question already has an answer here:



  • How many fixed points in a permutation

    2 answers



A person writes letters to six friends and their addresses to corresponding envelopes. In how many ways can the letters be placed in the envelopes so that at least two of them are in wrong envelopes?










share|cite|improve this question















marked as duplicate by Peter Taylor, Jendrik Stelzner, amWhy discrete-mathematics
Users with the  discrete-mathematics badge can single-handedly close discrete-mathematics questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
Sep 7 at 13:15


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.










  • 6




    Note: you can never have only $1$ letter in the wrong envelope.
    – Mohammad Zuhair Khan
    Sep 7 at 10:20






  • 2




    @MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
    – Henry
    Sep 7 at 10:53














up vote
-1
down vote

favorite













This question already has an answer here:



  • How many fixed points in a permutation

    2 answers



A person writes letters to six friends and their addresses to corresponding envelopes. In how many ways can the letters be placed in the envelopes so that at least two of them are in wrong envelopes?










share|cite|improve this question















marked as duplicate by Peter Taylor, Jendrik Stelzner, amWhy discrete-mathematics
Users with the  discrete-mathematics badge can single-handedly close discrete-mathematics questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
Sep 7 at 13:15


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.










  • 6




    Note: you can never have only $1$ letter in the wrong envelope.
    – Mohammad Zuhair Khan
    Sep 7 at 10:20






  • 2




    @MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
    – Henry
    Sep 7 at 10:53












up vote
-1
down vote

favorite









up vote
-1
down vote

favorite












This question already has an answer here:



  • How many fixed points in a permutation

    2 answers



A person writes letters to six friends and their addresses to corresponding envelopes. In how many ways can the letters be placed in the envelopes so that at least two of them are in wrong envelopes?










share|cite|improve this question
















This question already has an answer here:



  • How many fixed points in a permutation

    2 answers



A person writes letters to six friends and their addresses to corresponding envelopes. In how many ways can the letters be placed in the envelopes so that at least two of them are in wrong envelopes?





This question already has an answer here:



  • How many fixed points in a permutation

    2 answers







combinatorics discrete-mathematics






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Sep 7 at 10:26









N. F. Taussig

39.7k93153




39.7k93153










asked Sep 7 at 10:15









user9640947

366




366




marked as duplicate by Peter Taylor, Jendrik Stelzner, amWhy discrete-mathematics
Users with the  discrete-mathematics badge can single-handedly close discrete-mathematics questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
Sep 7 at 13:15


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.






marked as duplicate by Peter Taylor, Jendrik Stelzner, amWhy discrete-mathematics
Users with the  discrete-mathematics badge can single-handedly close discrete-mathematics questions as duplicates and reopen them as needed.

StackExchange.ready(function()
if (StackExchange.options.isMobile) return;

$('.dupe-hammer-message-hover:not(.hover-bound)').each(function()
var $hover = $(this).addClass('hover-bound'),
$msg = $hover.siblings('.dupe-hammer-message');

$hover.hover(
function()
$hover.showInfoMessage('',
messageElement: $msg.clone().show(),
transient: false,
position: my: 'bottom left', at: 'top center', offsetTop: -7 ,
dismissable: false,
relativeToBody: true
);
,
function()
StackExchange.helpers.removeMessages();

);
);
);
Sep 7 at 13:15


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.









  • 6




    Note: you can never have only $1$ letter in the wrong envelope.
    – Mohammad Zuhair Khan
    Sep 7 at 10:20






  • 2




    @MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
    – Henry
    Sep 7 at 10:53












  • 6




    Note: you can never have only $1$ letter in the wrong envelope.
    – Mohammad Zuhair Khan
    Sep 7 at 10:20






  • 2




    @MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
    – Henry
    Sep 7 at 10:53







6




6




Note: you can never have only $1$ letter in the wrong envelope.
– Mohammad Zuhair Khan
Sep 7 at 10:20




Note: you can never have only $1$ letter in the wrong envelope.
– Mohammad Zuhair Khan
Sep 7 at 10:20




2




2




@MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
– Henry
Sep 7 at 10:53




@MohammadZuhairKhan - you can if one envelope is empty and another contains two letters, though this question probably assumes each envelope contains exactly one letter
– Henry
Sep 7 at 10:53










1 Answer
1






active

oldest

votes

















up vote
4
down vote



accepted










If the person is placing the letters in the envelopes at random, and the order matters, there will be $6! = 720$ ways of placing the letters, and only of those has all of the letters placed correctly. So there are $719$ ways of making a mistake. (Note that one mistake means at least 2 are incorrect)






share|cite|improve this answer



























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    4
    down vote



    accepted










    If the person is placing the letters in the envelopes at random, and the order matters, there will be $6! = 720$ ways of placing the letters, and only of those has all of the letters placed correctly. So there are $719$ ways of making a mistake. (Note that one mistake means at least 2 are incorrect)






    share|cite|improve this answer
























      up vote
      4
      down vote



      accepted










      If the person is placing the letters in the envelopes at random, and the order matters, there will be $6! = 720$ ways of placing the letters, and only of those has all of the letters placed correctly. So there are $719$ ways of making a mistake. (Note that one mistake means at least 2 are incorrect)






      share|cite|improve this answer






















        up vote
        4
        down vote



        accepted







        up vote
        4
        down vote



        accepted






        If the person is placing the letters in the envelopes at random, and the order matters, there will be $6! = 720$ ways of placing the letters, and only of those has all of the letters placed correctly. So there are $719$ ways of making a mistake. (Note that one mistake means at least 2 are incorrect)






        share|cite|improve this answer












        If the person is placing the letters in the envelopes at random, and the order matters, there will be $6! = 720$ ways of placing the letters, and only of those has all of the letters placed correctly. So there are $719$ ways of making a mistake. (Note that one mistake means at least 2 are incorrect)







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Sep 7 at 11:15









        MRobinson

        74015




        74015












            這個網誌中的熱門文章

            How to combine Bézier curves to a surface?

            Carbon dioxide

            Why am i infinitely getting the same tweet with the Twitter Search API?