If George's driveway is a rectangle 12.2 m by 3.0 m, its dimensions in cm are
... 1220 cm long × 300 cm wide × 2 cm deep
Thus the volume of gravel required is
... (1220 × 300 × 2) cm³ = 732,000 cm³
George needs about 0.732 bags, so he will probably need to buy 1 bag.