A pitcher contains 17.5 cups of iced tea. you drink 0.75 cup of tea each morning and 1.75 cups of tea each evening. when will you run out of iced tea?

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! )