Date: 9/03/2013 23:16:55
From: OCDC
ID: 277364
Subject: Playing cards
How many 5-card combinations are there in a single deck of cards?
How many in two decks?
Please show working.
(This amn’t anyone’s homework, but I was too tired to work it out myself. I see that Mr Turing is back; please bump it for him if no-one else cares.)
Date: 9/03/2013 23:27:34
From: esselte
ID: 277371
Subject: re: Playing cards
Isn’t it just 5^52=2.22044046e+36? ie a fair few.
Date: 9/03/2013 23:35:09
From: esselte
ID: 277372
Subject: re: Playing cards
Wait, it depends on whether the order that the cards is important or not?
If its not important, it would be 52 × 51 × 5 = 13,260.
I think… But I don’t know. I not good at maths. Shouldn’t have said anything. Forget i was here, please. Sorry :)
Date: 9/03/2013 23:35:20
From: diddly-squat
ID: 277373
Subject: re: Playing cards
1 deck —> nCr 52 5 = 2,598,960
2 deck —> nCr 104 5 = 91,962,520
Date: 9/03/2013 23:35:21
From: sibeen
ID: 277374
Subject: re: Playing cards
52!/5!(52-5)!
= 52!/(5! *47!)
err, get out mathcad…2598960
For the two packs it will be 104!/ 5!(104-5)! = 104!/(5!*99!) = 91962520
Date: 9/03/2013 23:36:55
From: esselte
ID: 277375
Subject: re: Playing cards
…depends on whether the order that the cards are drawn is significant or not…. I meant to say.
Date: 9/03/2013 23:37:02
From: OCDC
ID: 277376
Subject: re: Playing cards
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
Date: 9/03/2013 23:39:22
From: sibeen
ID: 277377
Subject: re: Playing cards
I, of course, have the only correct answer, as the question asked “to show workings”.
diddly gets half marks :)
Date: 9/03/2013 23:40:47
From: diddly-squat
ID: 277378
Subject: re: Playing cards
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
Combination —> order doesn’t matter
Permertation —> order does matter
Date: 9/03/2013 23:40:51
From: diddly-squat
ID: 277379
Subject: re: Playing cards
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
Combination —> order doesn’t matter
Permertation —> order does matter
Date: 9/03/2013 23:41:31
From: diddly-squat
ID: 277380
Subject: re: Playing cards
sibeen said:
I, of course, have the only correct answer, as the question asked “to show workings”.
diddly gets half marks :)
Dude.. I showed how to work a calculator to get the answer…
Date: 9/03/2013 23:42:21
From: OCDC
ID: 277381
Subject: re: Playing cards
diddly-squat said:
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
Combination —> order doesn’t matter
Permertation —> order does matter
*permutation
Date: 9/03/2013 23:42:34
From: esselte
ID: 277382
Subject: re: Playing cards
Diddly squat and sibeen agree with each other, and seem to know what they are talking about.
I, on the other hand, seem to have got everything wrong.
Date: 9/03/2013 23:43:56
From: Angus Prune
ID: 277383
Subject: re: Playing cards
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
I remember learning this stuff in yr 11. Too bad I don’t remember what any of it was…
Date: 9/03/2013 23:44:09
From: sibeen
ID: 277384
Subject: re: Playing cards
>Dude.. I showed how to work a calculator to get the answer…
Yes, but I showed an equation that can easily be worked out without recourse to electronic calculating machines :)
Date: 9/03/2013 23:44:46
From: OCDC
ID: 277385
Subject: re: Playing cards
Angus Prune said:
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
I remember learning this stuff in yr 11. Too bad I don’t remember what any of it was…
I learnt it in year 8 and tutored it for goodness knows how many years after, which makes it even more embarrassing.
Date: 9/03/2013 23:47:01
From: esselte
ID: 277387
Subject: re: Playing cards
diddly-squat said:
1 deck —> nCr 52 5 = 2,598,960
2 deck —> nCr 104 5 = 91,962,520
Just out of interest, what does 5^52 calculate? Anything? Or is it just a random assembly of numbers and operations with no significance to decks of cards and combinations of cards?
Date: 9/03/2013 23:48:17
From: diddly-squat
ID: 277388
Subject: re: Playing cards
OCDC said:
Angus Prune said:
OCDC said:
Ta. And no, the order doesn’t matter.
(Knew it was something simple, that I used to know.)
I remember learning this stuff in yr 11. Too bad I don’t remember what any of it was…
I learnt it in year 8 and tutored it for goodness knows how many years after, which makes it even more embarrassing.
Yeah but that was like a million years ago
Date: 9/03/2013 23:48:53
From: sibeen
ID: 277389
Subject: re: Playing cards
5^52 = 2.22*10^36
It just means 5 × 5 × 5 …with 52 fives.
Date: 9/03/2013 23:50:24
From: diddly-squat
ID: 277390
Subject: re: Playing cards
esselte said:
diddly-squat said:
1 deck —> nCr 52 5 = 2,598,960
2 deck —> nCr 104 5 = 91,962,520
Just out of interest, what does 5^52 calculate? Anything? Or is it just a random assembly of numbers and operations with no significance to decks of cards and combinations of cards?
5^52 simply equals 5 × 5 × 5 × 5 …. 52 times over
Date: 9/03/2013 23:52:13
From: diddly-squat
ID: 277391
Subject: re: Playing cards
Date: 9/03/2013 23:53:09
From: esselte
ID: 277392
Subject: re: Playing cards
So no significance to the question? It’s not, like, the number of possible combinations in 5 decks of cards or anything like that?
Date: 9/03/2013 23:53:39
From: sibeen
ID: 277393
Subject: re: Playing cards
Lucky you got that last one in. I was about to give you half marks again.
Date: 9/03/2013 23:54:23
From: sibeen
ID: 277394
Subject: re: Playing cards
Date: 9/03/2013 23:56:02
From: diddly-squat
ID: 277395
Subject: re: Playing cards
sibeen said:
Lucky you got that last one in. I was about to give you half marks again.
diddly 1.5
sibeen 1
Date: 9/03/2013 23:56:38
From: esselte
ID: 277396
Subject: re: Playing cards
sibeen said:
Nil, esselte.
Hah. My parents paid for a private school education for me. I guess the jokes on them :)
Date: 9/03/2013 23:57:06
From: Wocky
ID: 277397
Subject: re: Playing cards
esselte said:
So no significance to the question? It’s not, like, the number of possible combinations in 5 decks of cards or anything like that?
If I had 52 decks of 5 cards, and drew one card from each, the number of possible hands would be 5^52.
Date: 10/03/2013 00:00:36
From: esselte
ID: 277398
Subject: re: Playing cards
Aha. So My answer was actually correct, and it’s just that OCDC asked the wrong question.
I feel much better now. Thanks Wocky!
Date: 10/03/2013 00:02:15
From: Wocky
ID: 277399
Subject: re: Playing cards
esselte said:
Aha. So My answer was actually correct, and it’s just that OCDC asked the wrong question.
I feel much better now. Thanks Wocky!
I aim to please (:
Date: 10/03/2013 00:02:50
From: diddly-squat
ID: 277400
Subject: re: Playing cards
and the two deck answer only holds if you assume that all cards are unique, that is, there is a way to distinguish between the 5 hearts in one deck and the 5 hearts in the other.
Date: 10/03/2013 00:12:15
From: sibeen
ID: 277401
Subject: re: Playing cards
Good point, diddly. I didn’t consider that.
Date: 10/03/2013 00:22:52
From: Rule 303
ID: 277407
Subject: re: Playing cards
esselte said:
My parents paid for a private school education for me. I guess the jokes on them :)
Were apostrophes an optional extra, by any chance?
;-)
Date: 10/03/2013 00:35:51
From: esselte
ID: 277414
Subject: re: Playing cards
Rule 303 said:
esselte said:My parents paid for a private school education for me. I guess the jokes on them :)
Were apostrophes an optional extra, by any chance?
;-)
It was an Anglican school. We were too busy learning about God to be bothered by such minutiae.
Date: 10/03/2013 14:48:30
From: PM 2Ring
ID: 277675
Subject: re: Playing cards
diddly-squat said:
and the two deck answer only holds if you assume that all cards are unique, that is, there is a way to distinguish between the 5 hearts in one deck and the 5 hearts in the other.
Indeed. And if we don’t care which deck a card comes from, the answer is much smaller:
52C5 + 4×52C4 + 3×52C3 = 3748160.
That’s 52C5 combinations with no duplicated cards,
plus 4×52C4 combinations with one duplicated card,
and 3×52C3 with two duplicated cards.
Date: 10/03/2013 14:52:14
From: OCDC
ID: 277676
Subject: re: Playing cards
Date: 10/03/2013 15:01:15
From: PM 2Ring
ID: 277683
Subject: re: Playing cards
I just ran a little Python program to confirm my formula. It took 17 minutes to count all the combinations. (But I did check it before I posted using several smaller deck sizes).