How do you calculate the cost for paint?

[Chrissy]

I have a math project that requires me to find the volume and surface area of 3 rooms. I did that already but now i need to find out the cost to paint this room. it says:

"Students will calculate how many gallons of paint and how much it will cost to paint the walls of the room with 2 coats of paint, if 1 gallon of paint covers 250sq ft and costs $18.50 per gallon. Each room will be painted a different color."

Okay i have no clue how to do that. So how do you do that? oh btw the surfecae area for the first room is 1,980 sq ft. Well thats what I got. Did i do it wrong? The room is 11ft by 10ft by 8ft.
i forgot i need to include 7.5% sales tax.

Right now i am trying to figure out the cost of ONE room.