Question

A gallon of stain is enough to cover 200 square feet of decking. Bradley has two areas of decking he would like to cover with stain. One rectangular area is 23 feet by 10.4 feet, and the other is 10.5 feet by 7.2 feet. Which expression gives the number of gallons of stain Bradley will need?

Answer 1

He needs at least 2 gallons of the stain; though he will not use all of the second gallon

Answer 2

Answer:   $\frac{23\times 10.4 +10.5\times 7.2}{200}$  gallon

Step-by-step explanation:

A gallon of stain is enough to cover 200 square feet of decking.

⇒The quantity of stain is enough to cover 1 square feet = $\frac{1}{200}$ gallon.

Now, the total area of decking = Rectangle having the dimension 23 × 10.4 + Rectangle having the dimension 10.5 × 7.2

= ( 23 × 10.4 + 10.5 × 7.2 ) $feet^2$

⇒ The quantity of stain is enough to cover 1 square feet = $\frac{23\times 10.4 +10.5\times 7.2}{200}$  gallon

=  $\frac{314.8}{200}$

= 1.574 gallon.