A wooden fence 2 yards high and 70 yards long is to be painted on both sides. A gallon of paint will cover 200 square feet of area. How many gallons of paint must be purchased to complete the job?
a] 1 gallon
b] 3 gallons
c] 8 gallons
d]13 gallons
I'm thinking its 3 gallons, but I want to make sure.
2007-10-05 16:17:39 · 4 answers · asked by Anonymous in Education & Reference ➔ Homework Help
well, the fence is in yards and the area that 1 gallon will cover is in feet. So we either convert all our units to yards or all our units to feet. I prefer feets but the problem will work both ways.
So, 1 yard = 3 feet therefore
2 yards = 2*3 =6 feet.
that is the fence is 6 feet high.
70 yards = 70*3 = 210 feet
that is the fence is 210 feet long.
Now we calculate the area of the fence. We know that the formula for area is length time width. In this case is length times height. A= w * h
A = 210 * 6
A = 1260
However, the problem stated that we want to paint both sides of the fence. The number we got only cover 1 side of the fence. So, we must umltiply by 2 because there are 1260 sq-feet on one side and 1260 sq-feet on the other
total areas = 2 * A
= 2 * 1260
total area = 2520 sq-feet
just one more step. The problem says that 1 gallon of paint will cover 200 sq-feet. By logic if 1 gallon covers 200 sq-feet then 2 gallons will cover 400 sq-feet, 3 gallons 600 sq-feet so on and so forth. However, we are going backward. The opposite of multiplication is division. In other words how many times does 200 goes into 2520?
gallons needed = 2520 / 200
gallons needed = 12.6 gallons. Well, none of the answers are exactly 12.6. The closest one is 13 gallons but!!!! we know that they won't sell you 0.6 of a gallon. I guess you can buy a quart here and there but you will always have some left over. Plus you always use more than you need to so, isn't it better to round it up to 13 gallons just to be on the safe side and avoid another trip to the hardware store?
2007-10-05 16:31:44 · answer #1 · answered by mr_gees100_peas 6 · 1⤊ 0⤋
A yard is 3 feet, so the fence is 6 by 210 = 1260 square feet. Both sides is 2520 square feet. So 13 gallons is needed. .
2016-03-19 06:18:32 · answer #2 · answered by ? 3 · 0⤊ 0⤋
Don't forget it is BOTH sides:
6 ft (2 yards) x 210 ft (70 yards) = 1260 feet x 2= 2520 sq feet
2520 divided by 200=12 and then some
Isn't that right?
2007-10-05 16:22:58 · answer #3 · answered by barb j 4 · 1⤊ 0⤋
i think b] 3 gallons
2007-10-05 16:27:46 · answer #4 · answered by dani 1 · 0⤊ 1⤋