need some help from the math savvy

[sageridder]

I'm trying to get the odds of drawing a card for mtg.So 60 card deck, 4 copies of the card you want, your draw is 7 cards.What is the odds of drawing said card, even better if someone could show odds of drawing 1,2,3,or all 4.I simply don't know the math and am being told by someone it's like a 44% chance to draw 1.That just seems ridiculously high to me,any help appreciated.

[Davros]

4 copies of card - so :

First go - 4/60 chance = 6.67%
Now assuming each time you failed to draw
2nd go = 4/59
3rd go 4/58
etc
So the chance of drawing one of the 4 cards in 7 goes = 4/60 + 4/59 + 4/58 + 4/57 + 4/56 + 4/55 + 4/54
= 49.2%


If you think about it - you start with a 4/60 or one in fifteen chance of success - and you are having seven tries (seven being a little under half of fifteen) so there is no issue with teh number being too high at all.

As for the odds of drawing 2 or more - well that changes all about depending on what draw you get your cards (ie the odds of drawing 2 cards is fairly good if the first target card is drawn at the first attempt - but the odds declines with each failed attempt.

[Callum]

But then again, what deck has 60 cards? Most decks have 52 cards... 4 suites of 13. Unless you have 8 jokers...

So it's actually 4/52 + 4/51 + 4/50 + 4/49 + 4/48 + 4/47 + 4/46 = 57%

[Dundee Slaytern]

Originally posted by Callum: But then again, what deck has 60 cards? Most decks have 52 cards... 4 suites of 13. Unless you have 8 jokers... So it's actually 4/52 + 4/51 + 4/50 + 4/49 + 4/48 + 4/47 + 4/46 = 57%

sagerider mentioned 'mtg' in his post. 'Magic:The Gathering'.

[Callum]

Well shucks! [img]tongue.gif[/img]

[sageridder]

Thank You.

[ 07-29-2006, 02:15 PM: Message edited by: sageridder ]