Answer: $22
Step-by-step explanation:
The wall is 23 ft by 8 ft, so if you multiply both sides of the rectangle together, you get the area.
23 * 8 = 184 ft^2
Since the wall requires 2 coats of paint, that means you'll just need to double the area you need to cover (since you're covering it twice).
184 * 2 = 368 ft^2
Now that we know how much square feet of area we need to cover, we can try and figure out how many gallons of paint we need to cover said area.
One gallon of paint covers 320 ft^2, so we can divide the area we need to cover (368) by the area a single gallon can cover (320) to get the amount of gallons we need to cover the wall.
368 / 320 = 1.15 gallons
To cover the wall twice, we need 1.15 gallons of paint. Assuming we can't buy 0.15 of a gallon, we will just need to buy two full gallons. Each gallon is $11, so two gallons each costing $11 is:
2 * 11 = $22
Side note: IF you can buy 0.15 of a gallon, then just multiply 1.15 * 11 = $12.65