How many cookies does someone need to grab to be certain to obtain a flavor?












5












$begingroup$


I often found this riddle in many exams but I got often confused on how to tackle it. While it involves maths. I wonder if there is a subtle or a more layman method to obtain an answer using common sense?.



The problem which I'm about to describe isn't a specific homework problem. Is just a situation which I had imagined just now based on the kind of situation which often gets me confused. Okay here it goes:




A toddler want to grab some strawberry cookies. However there are
three flavors of those cookies in a jar, which just happen to be atop
of a refrigerator. There is a ladder in the kitchen, but the height of
that ladder isn't bigger enough for him to tell the difference between
which flavor of the cookies is which, all he can do is extend his arm
and take out the cookies from the jar. The child knows from his mom
that she made 10 of those strawberry cookies in the morning. However
he knows that the jar also has leftovers which he spotted on the night
before and these were 6 of vanilla flavor and 5 of chocolate chips.




Okay now comes the part where I often got stuck at:



What is the least amount of cookies that he has to take out from the jar to be certain that he has 4 of chocolate chips, 5 of vanilla and 7 of of strawberries?.



Now a second question



What is the least amount that he has to take out to be certain that he has all the strawberries and all chocolate chips?



And finally the third one



What is the least amount that he has to take from the jar to be certain that he has 1 of each flavor.



What I do remember from this situation is that when solving this riddle you often consider the most difficult scenario, in other words. He needs to take out let's say 10 in this case so with that he is certain that has strawberries. However I'm not very sure if this reasoning is valid.



Can somebody give me some help with this?



I'm slow at catching up ideas so, I'd like the answer could show or include the most details as possible and explain why certain decision or argument is taken.










share|improve this question









$endgroup$








  • 5




    $begingroup$
    Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
    $endgroup$
    – Ian MacDonald
    yesterday
















5












$begingroup$


I often found this riddle in many exams but I got often confused on how to tackle it. While it involves maths. I wonder if there is a subtle or a more layman method to obtain an answer using common sense?.



The problem which I'm about to describe isn't a specific homework problem. Is just a situation which I had imagined just now based on the kind of situation which often gets me confused. Okay here it goes:




A toddler want to grab some strawberry cookies. However there are
three flavors of those cookies in a jar, which just happen to be atop
of a refrigerator. There is a ladder in the kitchen, but the height of
that ladder isn't bigger enough for him to tell the difference between
which flavor of the cookies is which, all he can do is extend his arm
and take out the cookies from the jar. The child knows from his mom
that she made 10 of those strawberry cookies in the morning. However
he knows that the jar also has leftovers which he spotted on the night
before and these were 6 of vanilla flavor and 5 of chocolate chips.




Okay now comes the part where I often got stuck at:



What is the least amount of cookies that he has to take out from the jar to be certain that he has 4 of chocolate chips, 5 of vanilla and 7 of of strawberries?.



Now a second question



What is the least amount that he has to take out to be certain that he has all the strawberries and all chocolate chips?



And finally the third one



What is the least amount that he has to take from the jar to be certain that he has 1 of each flavor.



What I do remember from this situation is that when solving this riddle you often consider the most difficult scenario, in other words. He needs to take out let's say 10 in this case so with that he is certain that has strawberries. However I'm not very sure if this reasoning is valid.



Can somebody give me some help with this?



I'm slow at catching up ideas so, I'd like the answer could show or include the most details as possible and explain why certain decision or argument is taken.










share|improve this question









$endgroup$








  • 5




    $begingroup$
    Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
    $endgroup$
    – Ian MacDonald
    yesterday














5












5








5





$begingroup$


I often found this riddle in many exams but I got often confused on how to tackle it. While it involves maths. I wonder if there is a subtle or a more layman method to obtain an answer using common sense?.



The problem which I'm about to describe isn't a specific homework problem. Is just a situation which I had imagined just now based on the kind of situation which often gets me confused. Okay here it goes:




A toddler want to grab some strawberry cookies. However there are
three flavors of those cookies in a jar, which just happen to be atop
of a refrigerator. There is a ladder in the kitchen, but the height of
that ladder isn't bigger enough for him to tell the difference between
which flavor of the cookies is which, all he can do is extend his arm
and take out the cookies from the jar. The child knows from his mom
that she made 10 of those strawberry cookies in the morning. However
he knows that the jar also has leftovers which he spotted on the night
before and these were 6 of vanilla flavor and 5 of chocolate chips.




Okay now comes the part where I often got stuck at:



What is the least amount of cookies that he has to take out from the jar to be certain that he has 4 of chocolate chips, 5 of vanilla and 7 of of strawberries?.



Now a second question



What is the least amount that he has to take out to be certain that he has all the strawberries and all chocolate chips?



And finally the third one



What is the least amount that he has to take from the jar to be certain that he has 1 of each flavor.



What I do remember from this situation is that when solving this riddle you often consider the most difficult scenario, in other words. He needs to take out let's say 10 in this case so with that he is certain that has strawberries. However I'm not very sure if this reasoning is valid.



Can somebody give me some help with this?



I'm slow at catching up ideas so, I'd like the answer could show or include the most details as possible and explain why certain decision or argument is taken.










share|improve this question









$endgroup$




I often found this riddle in many exams but I got often confused on how to tackle it. While it involves maths. I wonder if there is a subtle or a more layman method to obtain an answer using common sense?.



The problem which I'm about to describe isn't a specific homework problem. Is just a situation which I had imagined just now based on the kind of situation which often gets me confused. Okay here it goes:




A toddler want to grab some strawberry cookies. However there are
three flavors of those cookies in a jar, which just happen to be atop
of a refrigerator. There is a ladder in the kitchen, but the height of
that ladder isn't bigger enough for him to tell the difference between
which flavor of the cookies is which, all he can do is extend his arm
and take out the cookies from the jar. The child knows from his mom
that she made 10 of those strawberry cookies in the morning. However
he knows that the jar also has leftovers which he spotted on the night
before and these were 6 of vanilla flavor and 5 of chocolate chips.




Okay now comes the part where I often got stuck at:



What is the least amount of cookies that he has to take out from the jar to be certain that he has 4 of chocolate chips, 5 of vanilla and 7 of of strawberries?.



Now a second question



What is the least amount that he has to take out to be certain that he has all the strawberries and all chocolate chips?



And finally the third one



What is the least amount that he has to take from the jar to be certain that he has 1 of each flavor.



What I do remember from this situation is that when solving this riddle you often consider the most difficult scenario, in other words. He needs to take out let's say 10 in this case so with that he is certain that has strawberries. However I'm not very sure if this reasoning is valid.



Can somebody give me some help with this?



I'm slow at catching up ideas so, I'd like the answer could show or include the most details as possible and explain why certain decision or argument is taken.







riddle probability word-problem






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked yesterday









Chris Steinbeck BellChris Steinbeck Bell

1514




1514








  • 5




    $begingroup$
    Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
    $endgroup$
    – Ian MacDonald
    yesterday














  • 5




    $begingroup$
    Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
    $endgroup$
    – Ian MacDonald
    yesterday








5




5




$begingroup$
Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
$endgroup$
– Ian MacDonald
yesterday




$begingroup$
Okay, a few things. 1: if the cookies were made this morning, they are very likely on top of the other cookies within the jar, so the selection should be trivial. 2: Since when do toddlers take less than all of the cookies?
$endgroup$
– Ian MacDonald
yesterday










1 Answer
1






active

oldest

votes


















7












$begingroup$

Originally there are;




10 S, 6 V and 5C




For the first case where he wants to have 7 S, 5 V and , 4 C. (so we dont want to have 3S, 1V and 1C)



In the worst case scenario;




we need to think that he is very unlucky, while taking out cookies, he takes all strawberries first, where there are 10 of them, so extra 3 cookies, and etc.




so




He has to take out 10S+6V+4C = 20 cookies to guarantee he can have 7S, 5V and 4C. Put the extras back later.




I do not want to continue for the rest since the same methodology works for them too:




in the worst case scenario, take out first the type of cookie which has the most extras (number of cookies available - wanted amount of cookies), then second most and lastly the least one.




This will give you the number of cookies to guarantee to have some specific number of cookies.






share|improve this answer











$endgroup$













    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: "559"
    };
    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: false,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: null,
    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
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81006%2fhow-many-cookies-does-someone-need-to-grab-to-be-certain-to-obtain-a-flavor%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    7












    $begingroup$

    Originally there are;




    10 S, 6 V and 5C




    For the first case where he wants to have 7 S, 5 V and , 4 C. (so we dont want to have 3S, 1V and 1C)



    In the worst case scenario;




    we need to think that he is very unlucky, while taking out cookies, he takes all strawberries first, where there are 10 of them, so extra 3 cookies, and etc.




    so




    He has to take out 10S+6V+4C = 20 cookies to guarantee he can have 7S, 5V and 4C. Put the extras back later.




    I do not want to continue for the rest since the same methodology works for them too:




    in the worst case scenario, take out first the type of cookie which has the most extras (number of cookies available - wanted amount of cookies), then second most and lastly the least one.




    This will give you the number of cookies to guarantee to have some specific number of cookies.






    share|improve this answer











    $endgroup$


















      7












      $begingroup$

      Originally there are;




      10 S, 6 V and 5C




      For the first case where he wants to have 7 S, 5 V and , 4 C. (so we dont want to have 3S, 1V and 1C)



      In the worst case scenario;




      we need to think that he is very unlucky, while taking out cookies, he takes all strawberries first, where there are 10 of them, so extra 3 cookies, and etc.




      so




      He has to take out 10S+6V+4C = 20 cookies to guarantee he can have 7S, 5V and 4C. Put the extras back later.




      I do not want to continue for the rest since the same methodology works for them too:




      in the worst case scenario, take out first the type of cookie which has the most extras (number of cookies available - wanted amount of cookies), then second most and lastly the least one.




      This will give you the number of cookies to guarantee to have some specific number of cookies.






      share|improve this answer











      $endgroup$
















        7












        7








        7





        $begingroup$

        Originally there are;




        10 S, 6 V and 5C




        For the first case where he wants to have 7 S, 5 V and , 4 C. (so we dont want to have 3S, 1V and 1C)



        In the worst case scenario;




        we need to think that he is very unlucky, while taking out cookies, he takes all strawberries first, where there are 10 of them, so extra 3 cookies, and etc.




        so




        He has to take out 10S+6V+4C = 20 cookies to guarantee he can have 7S, 5V and 4C. Put the extras back later.




        I do not want to continue for the rest since the same methodology works for them too:




        in the worst case scenario, take out first the type of cookie which has the most extras (number of cookies available - wanted amount of cookies), then second most and lastly the least one.




        This will give you the number of cookies to guarantee to have some specific number of cookies.






        share|improve this answer











        $endgroup$



        Originally there are;




        10 S, 6 V and 5C




        For the first case where he wants to have 7 S, 5 V and , 4 C. (so we dont want to have 3S, 1V and 1C)



        In the worst case scenario;




        we need to think that he is very unlucky, while taking out cookies, he takes all strawberries first, where there are 10 of them, so extra 3 cookies, and etc.




        so




        He has to take out 10S+6V+4C = 20 cookies to guarantee he can have 7S, 5V and 4C. Put the extras back later.




        I do not want to continue for the rest since the same methodology works for them too:




        in the worst case scenario, take out first the type of cookie which has the most extras (number of cookies available - wanted amount of cookies), then second most and lastly the least one.




        This will give you the number of cookies to guarantee to have some specific number of cookies.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited yesterday

























        answered yesterday









        OrayOray

        16.1k437157




        16.1k437157






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Puzzling 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.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fpuzzling.stackexchange.com%2fquestions%2f81006%2fhow-many-cookies-does-someone-need-to-grab-to-be-certain-to-obtain-a-flavor%23new-answer', 'question_page');
            }
            );

            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







            Popular posts from this blog

            He _____ here since 1970 . Answer needed [closed]What does “since he was so high” mean?Meaning of “catch birds for”?How do I ensure “since” takes the meaning I want?“Who cares here” meaningWhat does “right round toward” mean?the time tense (had now been detected)What does the phrase “ring around the roses” mean here?Correct usage of “visited upon”Meaning of “foiled rail sabotage bid”It was the third time I had gone to Rome or It is the third time I had been to Rome

            Bunad

            Færeyskur hestur Heimild | Tengill | Tilvísanir | LeiðsagnarvalRossið - síða um færeyska hrossið á færeyskuGott ár hjá færeyska hestinum