SOLUTION: Determine the number of cans of paint needed to paint three rooms of a house (walls and ceiling). Each room is 12 feet by 10 feet with 8 foot ceilings. Each room contains a 4 foot

Algebra ->  Test -> SOLUTION: Determine the number of cans of paint needed to paint three rooms of a house (walls and ceiling). Each room is 12 feet by 10 feet with 8 foot ceilings. Each room contains a 4 foot       Log On


   



Question 824153: Determine the number of cans of paint needed to paint three rooms of a house (walls and ceiling). Each room is 12 feet by 10 feet with 8 foot ceilings. Each room contains a 4 foot by 5 foot window and a 3 foot by 7 foot door. A can of paint is 1 gallon and covers 250 square feet.
please help me

Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Surface Area of a room:
2%2812%2A8%29%2B2%2810%2A8%29%2B12%2A10 ignoring the door and window.
Accounting for the door and window, room area needing paint is %2812%2A8%29%2B2%2810%2A8%29%2B12%2A10-%284%2A5%2B3%2A7%29 square feet.

A specific answer requires knowing the number of these rooms. Let r = how many rooms like this need painting.

Surface area to paint for the r rooms is r%28%2812%2A8%29%2B2%2810%2A8%29%2B12%2A10-%284%2A5%2B3%2A7%29%29

How many gallons of paint needed,

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
To picture the rooms, the areas of the ceilings are
10 x 12 ft2
If you measure from floor to ceiling, the height
of each room is 8 ft
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That tells you that each room has two walls
that are 8 x 12 ft2
and two walls that are 8 x 10 ft2
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The ceilings are each 10 x 12 ft2
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So, for one of the 3 rooms, you have:
Area[1] = +2%2A8%2A12+%2B+2%2A8%2A10+%2B+10%2A12+
Area[1] = +192+%2B+160+%2B+120+
Area[1] = +472+ ft2
-----------------
The total area of the 3 rooms is:
Area[3] = +3%2A472+
Area[3] = +1416+ ft2
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You have to subtract the areas of the window
and a door in each room:
Area[1'] = +4%2A5+%2B+3%2A7+
Area[1'] = +41+
The total area to subtract for the 3 rooms is:
Area[3'] = +3%2A41+
Area[3'] = +123+
-----------------
The area that must be painted is:
Area = +1416+-+123+
Area = +1293+
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To find the number of cans of paint needed:
+1293+%2F+250+=+5.172+
They won't sell you part of a can of paint,
so you need 6 cans of paint