Probability of Flopping a Straight with these 2 cards

AK,AQ,AJ,AT,K9,Q8,J7,T6,95,84,62,A5,A4,A3,A2 0.3% 332 to 1
KQ,KJ,KT,Q9,J8,T7,96,85,74,63,52,42,32 0.7% 142 to 1
QJ,QT,J9,T8,97,86,64,53,43 1% 99 to 1
JT,T9,98,76,65,64 1.2% 76 to 1
How? (12/50)*(8/49)*(4/48)=0.003  
12/50 = chance of getting K or Q or J 
8/49 = chance of getting the other cards
4/48 = chance of getting the last card