Mary jane is organizing her cds. each cd case has an area of 16 in2. the height of a stack is 5 inches. what is the volume of a stack? a) 45 in3 b) 60 in3 c) 80 in3 d) 90 in3

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )