Salma is at the grand opening celebration of a supermarket. she spins a wheel with 10 equal-sized slices, as shown below. the wheel has 7 black slices, 2 grey slices, and 1 white slice. when the wheel is spun, the arrow stops on a slice at random. if the arrow stops on the border of two slices, the wheel is spun again. if the arrow stops on a black slice, then nicole wins a gift card. find the odds against nicole winning a gift card.
A) 2:7
B) 7:2
C) 3:1
D) 1:3
