Vector a~ points south. vector b~ points west. what is the direction of their cross product a~ × b~ ?

Can i have some possible answers if there are any

16 balls. 

Let's call x the total number of golf balls that Ricardo had before he lost the first 6 balls. (x - 6).
Then he bought 12 more and lost 4 so basically 12 - 4 = 8
Add that to the equation: (x-6) + 8
And now that he has 18 golf balls at end of the second day the total must add to 18.

Full equation: (x-6) + 8 = 18

(x-6) + 8 = 18
(x-6) = 18 - 8 <-- Transpose
(x-6) = 10
16 - 6 = 10 <-- What would x have to be inoder to make this equation true? 16!
So x = 16

16 is the number of golf balls the Ricardo began with.