I'd say its D but im not quite sure, its what makes most sense to me.
H = -2r + s/πr
C = 3A-a-b
If you need step by step comment
How many cubic feet are in a carton measuring 6 feet, 8 inches by 3 yards by 4.5 inches?
$55 this is shown by doing 80/100=0.80. and 0.80*55=this is the answer