[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.