A chicken coop is being made in the shape shown below with the dimensions shown. If fencing must be placed on each side of the pen and it costs $2.50 per foot, how much will it cost to enclose this pen? Show
your work.

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! )