Hello people i want to tell you that i want to influence good on their work and have fun. Do this one problem for me:87654x987654
WIthout calucator and explination:)

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! )