[jay_shark]

[ QUOTE ]
whats wrong with this?->

(12/52) + (12/51) + (12/50) = K,Q,or J hitting ~70.5%

[/ QUOTE ]

You may be thinking of the inclusion/exclusion formula .

P(AuBuc) = P(A)+P(B)+P(C) - P(AB)-P(AC) -P(BC) +P(ABC)

Where A is the event the first card is a k,q,j.
B is the event the second card is a k,q,j
C is the event the third card is a k,q,j .

So we have 12/52*3 - 12/52*11/49*3 + 12/52*11/51*10/50 = 0.552941176

You may want to look up Venn diagrams to get a visualization of what's happening here .