Question

Anoushka needs to stain the circular wooden deck in the backyard. The deck has a diameter of 30 feet. A gallon of stain covers approximately 250 square feet. Each gallon is $33.99. How much will Anoushka spend in order to stain the deck? Use 3.14 to approximate .

Answer 1

$101.97

Explanation:

Diameter of circular wooden deck = 30 ft

Radius of the deck = ½ of diameter = ½*30 = 15 ft

Area of deck = πr² = 3.14*15² = 706.5 ft²

1 gallon covers 250 ft² (1 gallon = 250 ft²)

Let x be the number of gallons that will cover 706.5 ft² of the deck

Thus:

1 gallon = 250 ft²

x = 706.5 ft²

Cross multiply

1*706.5 = 250*x

706.5/250 = x

2.826 = x

Number of gallons to cover the deck is approximately 3 gallons (approximated to nearest whole number). Since the we can't buy a gallon that is not full, we approximate to give us 3 gallons.

1 gallon cost $33.99 (1 gallon = $33.99)

3 gallons cost: 3*33.99 = $101.97