How many ways can you arrange a deck of cards? - Yannay Khaikin

Na koliko načina možete da poređate špil karata? - Janaj Kajkin (Yannay Khaikin)

1,665,654 views

2014-03-27 ・ TED-Ed


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How many ways can you arrange a deck of cards? - Yannay Khaikin

Na koliko načina možete da poređate špil karata? - Janaj Kajkin (Yannay Khaikin)

1,665,654 views ・ 2014-03-27

TED-Ed


Please double-click on the English subtitles below to play the video.

Prevodilac: Miloš Milosavljević Lektor: Mile Živković
00:06
Pick a card, any card.
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Izaberite kartu. Bilo koju.
00:09
Actually, just pick up all of them and take a look.
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U stvari, uzmite ih sve i pogledajte.
00:12
This standard 52-card deck has been used for centuries.
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Ovaj standardni špil od 52 karte koristi se vekovima.
00:15
Everyday, thousands just like it
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Svakodnevno, hiljade ovakvih
00:18
are shuffled in casinos all over the world,
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se meša u kazinima širom sveta
00:21
the order rearranged each time.
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i redosled karata se menja svaki put.
00:23
And yet, every time you pick up a well-shuffled deck
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Svaki put kad uzmete dobro promešan špil
00:26
like this one,
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kao što je ovaj,
00:27
you are almost certainly holding
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skoro sigurno ćete imati
00:29
an arrangement of cards
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raspored karata
00:30
that has never before existed in all of history.
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koji nikada u istoriji nije postojao.
00:33
How can this be?
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Kako je to moguće?
00:35
The answer lies in how many different arrangements
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Odgovor leži u tome koliko ima mogućih različitih rasporeda
00:37
of 52 cards, or any objects, are possible.
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52 karte, ili bilo kojih drugih predmeta.
00:42
Now, 52 may not seem like such a high number,
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Možda 52 ne izgleda kao naročito veliki broj,
00:45
but let's start with an even smaller one.
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ali hajde da krenemo sa još manjim.
00:48
Say we have four people trying to sit
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Recimo da imamo četvoro ljudi koji pokušavaju da sednu
00:49
in four numbered chairs.
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na četiri numerisane stolice.
00:52
How many ways can they be seated?
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Na koliko načina mogu da se rasporede?
00:54
To start off, any of the four people can sit
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Za početak, svako od njih četvoro može da sedne
00:56
in the first chair.
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na prvu stolicu.
00:57
One this choice is made,
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Kad je ovaj izbor napravljen,
00:59
only three people remain standing.
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samo troje ostaje da stoji.
01:01
After the second person sits down,
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Pošto druga osoba sedne,
01:03
only two people are left as candidates
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ostaje samo dva kandidata
01:05
for the third chair.
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za treću stolicu.
01:06
And after the third person has sat down,
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A kad treća osoba sedne,
01:08
the last person standing has no choice
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poslednja koja je ostala nema drugog izbora,
01:10
but to sit in the fourth chair.
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nego da sedne na četvrtu stolicu.
01:12
If we manually write out all the possible arrangements,
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Ako ručno napišemo sve moguće rasporede,
01:15
or permutations,
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ili permutacije,
01:16
it turns out that there are 24 ways
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ispostavlja se da postoji 24 načina
01:18
that four people can be seated into four chairs,
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da se četvoro ljudi rasporedi na 4 stolice,
01:22
but when dealing with larger numbers,
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ali kada radimo sa većim brojevima,
01:23
this can take quite a while.
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to može da potraje.
01:25
So let's see if there's a quicker way.
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Pa, da vidimo da li postoji brži način.
01:27
Going from the beginning again,
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Ako krenemo opet od početka,
01:29
you can see that each of the four initial choices
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možete videti da svaka od prvobitne 4 mogućnosti
01:31
for the first chair
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za prvu stolicu
01:32
leads to three more possible choices for the second chair,
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vodi do još tri mogućnosti za drugu stolicu,
01:35
and each of those choices
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a svaka od tih mogućnosti
01:37
leads to two more for the third chair.
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vodi do još dve za treću stolicu.
01:39
So instead of counting each final scenario individually,
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Pa umesto brojanja svakog pojedinačnog rezultata,
01:43
we can multiply the number of choices for each chair:
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možemo pomnožiti broj mogućnosti za svaku stolicu:
01:46
four times three times two times one
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4 x 3 x 2 x 1,
01:49
to achieve the same result of 24.
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da bismo dobili isti rezultat: 24.
01:51
An interesting pattern emerges.
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Pojavljuje se zanimljiv obrazac.
01:53
We start with the number of objects we're arranging,
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Počinjemo sa brojem predmeta koje raspoređujemo,
01:56
four in this case,
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u ovom slučaju četiri,
01:58
and multiply it by consecutively smaller integers
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i množimo ga sledećim manjim celim brojevima
02:00
until we reach one.
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dok ne stignemo do 1.
02:02
This is an exciting discovery.
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Ovo je bilo uzbudljivo otkriće,
02:04
So exciting that mathematicians have chosen
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do te mere, da su matematičari odlučili
02:06
to symbolize this kind of calculation,
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da predstave ovu operaciju
02:08
known as a factorial,
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poznatu kao faktorijel,
02:10
with an exclamation mark.
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simbolom uzvičnika.
02:12
As a general rule, the factorial of any positive integer
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Kao opšte pravilo, faktorijel bilo kog pozitivnog celog broja
02:15
is calculated as the product
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se računa kao proizvod
02:17
of that same integer
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tog istog celog broja
02:18
and all smaller integers down to one.
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i svih manjih celih brojeva od njega, sve do broja 1.
02:21
In our simple example,
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U našem jednostavnom primeru,
02:23
the number of ways four people
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broj načina na koje se četvoro ljudi
02:24
can be arranged into chairs
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može rasporediti na stolice
02:26
is written as four factorial,
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je napisan kao četiri faktorijel,
02:28
which equals 24.
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što iznosi 24.
02:29
So let's go back to our deck.
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Da se vratimo na naš špil.
02:31
Just as there were four factorial ways
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Isto kao što je bilo četiri faktorijel načina
02:33
of arranging four people,
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raspoređivanja četvoro ljudi,
02:35
there are 52 factorial ways
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tako postoji 52 faktorijel načina
02:37
of arranging 52 cards.
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da se rasporede 52 karte.
02:40
Fortunately, we don't have to calculate this by hand.
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Srećom, ne moramo to da računamo ručno.
02:43
Just enter the function into a calculator,
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Samo upišite funkciju u digitron
02:45
and it will show you that the number of
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i on će vam pokazati da je
02:46
possible arrangements is
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broj mogućih rasporeda
02:47
8.07 x 10^67,
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8.07 x 10^67,
02:52
or roughly eight followed by 67 zeros.
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što je otprilike - broj 8 sa 67 nula.
02:55
Just how big is this number?
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Koliki je ustvari ovaj broj?
02:57
Well, if a new permutation of 52 cards
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Pa, ako bi se svaka nova permutacija 52 karte
02:59
were written out every second
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zapisivala svake sekunde
03:01
starting 13.8 billion years ago,
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počevši od pre 13,8 milijardi godina,
03:04
when the Big Bang is thought to have occurred,
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kada se veruje da se dogodio Veliki prasak,
03:06
the writing would still be continuing today
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zapisivanje bi trajalo i danas
03:09
and for millions of years to come.
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i nastavilo bi se još milionima godina.
03:11
In fact, there are more possible
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U stvari, ima više
03:13
ways to arrange this simple deck of cards
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mogućih načina rasporeda ovog jednostavnog špila karata,
03:16
than there are atoms on Earth.
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nego što ima atoma na Zemlji.
03:18
So the next time it's your turn to shuffle,
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Zato, sledeći put kad bude bio vaš red da mešate,
03:20
take a moment to remember
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setite se da
03:22
that you're holding something that
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možda držite nešto
03:23
may have never before existed
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što nikada ranije nije postojalo
03:25
and may never exist again.
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i neće ni postojati.
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