
Grigori S. answered 04/29/13
Certified Physics and Math Teacher G.S.
First card has 52 chances to selected, the second one - 51, third - 50, and fourth one - 49 chances.
Their product equals to the number of permutations without repetiiton = 52X51X50X49 = 6,497,400.
But in each set of four cards they can be rearranged in 4!=1x2x3x4 = 24 times. To get the number without replacement yiou have to divide 6,497,400 by 24. It equals 270, 725.