There are three walls in Jordan’s living room. The three walls, shown here, are 12 feet, 9 feet and 10 feet wide, respectively. Each wall has a height of 8 feet with a 6-inch baseboard along the bottom. The largest of the three walls contains a window that measures 5 feet by 6 feet. Jordan plans to paint the three walls of his living room by mixing together some paint he already has, which includes white #2, magenta #3, red #4, yellow #5 and green #6. Jordan has decided to paint two of the walls a pale goldenrod and the third wall will be painted burnt umber.

Question

Suppose that 1 gallon of paint is used to cover 400 sq feet. Jordan plans to apply four coats of the goldenrod paint mixture to the 12-foot wall and the 9-foot wall leaving only the window and baseboard unpainted. How many gallons of the goldenrod paint mixture will he need? Express your answer as a decimal to the nearest hundredth.

Answer 1

I will ignore all the jibberish about paint colour names and simply use colour A for the large wall and colour B for the other walls

area of large wall = 12(7.5) - 5(6) = 60 square feet
area of other two walls = (9)(7.5) + 10(7.5) = 142.5 square feet

he will need 60/240 or .25 gallon of colour A for the large wall, which would be 1 quart
he will need 142.5/400 or .35625 gallons of colour B, so he needs 2 quarts of colour B

It seems silly to ask for accuracy to the nearest hundredth in the number of gallons needed.
Can you imagine walking into a paint store and asking for .356 of a gallon of paint?

Answer 2

what is the y-coordinate of the point of intersection of the graphs of x+2y=-6 and 2x+y=24?