Question

use the information given below to answer the questions. joann wants to estimate the cost to repaint her living room. joann measures her living room and finds that the floor dimensions are a length of 12 feet and a width of 12 feet. the walls are 9 feet tall. (a) find the area of her living room. hint: you must find the total area of all four walls. for the purpose of the estimate, dont worry about doors or windows. (include units in your answer. more information.) the total area of joanns living room walls is . (b) the paint joann wants covers 144 square feet per gallon. how many gallons of paint does joann need to buy? (include units in your answer. more information.) joann needs to buy of paint. (c) the paint costs $12.98 per gallon. how much will it cost joann to buy the paint? (include units in your answer. more information.) it will cost for joann to buy the paint.

Explanation:

Step1: Calculate area of two - types of walls

There are two pairs of opposite walls. One pair has dimensions 12 feet (length) and 9 feet (height), and the other pair has dimensions 12 feet (width) and 9 feet (height).
The area of the first - type of wall (length×height) is $A_1 = 12\times9 = 108$ square feet, and there are 2 such walls. The area of the second - type of wall (width×height) is $A_2=12\times9 = 108$ square feet, and there are 2 such walls.
The total wall area $A = 2\times(12\times9)+2\times(12\times9)=2\times108 + 2\times108=432$ square feet.

Step2: Calculate gallons of paint

If 1 gallon of paint covers 144 square feet, then the number of gallons of paint $n$ needed is $n=\frac{A}{144}$. Substituting $A = 432$ square feet, we get $n=\frac{432}{144}=3$ gallons.

Step3: Calculate cost of paint

If each gallon of paint costs $12.98, then the total cost $C$ of 3 gallons of paint is $C = 12.98\times3=38.94$.

Answer:

(a) 432 square feet
(b) 3 gallons
(c) $38.94