Alexi needs to paint the four interior walls of a large rectangular barn. The length of the barn is 80 feet, the width is 40 feet, and the height is 30 feet. The paint costs $28 per gallon, and each gallon covers 400 square feet. 1. How much will it cost Alexi to paint these walls of the barn?

2. Alexi decides that he wants to paint the ceiling and floor as well. How many total square feet is he now covering and what will his new overall cost be?