[rminusq]

xCy, read x choose y, is the number of ways to be dealt y cards out of a choice of x.

Number of 4-card hands: 52C4 = 52*51*50*49/4! = 270725
Number of ways to get AAbc, where b and c are not aces: 4C2 [pick two of the four aces] * 48C2 [pick two non-aces] = 4*3/2 * 48*47/2 = 6768
The ratio is then 6768/270725 = 2.499%. So yeah, 2-3%.