Answer: The correct option is (C) $342.
Step-by-step explanation: Given that Mr. Williams is building a sand box for his children and is costs $228 for the sand if he builds a rectangular-sand box with dimensions 9 ft by 6 ft.
We are to find the cost of the sand if he decides to increase the size to [tex]13\frac{1}{2}~\textup{ft by }9~\textup{ft}.[/tex]
Since the box is empty from inside, so we will be considering the perimeter of the box, not area.
The perimeter of the rectangular-sand box with dimensions 9 ft by 6 ft is
[tex]P_1=2(9+6)=30~\textup{ft},[/tex]
and the perimeter of the rectangular-sand box with dimensions [tex]13\frac{1}{2}~\textup{ft by }9~\textup{ft}.[/tex] is
[tex]P_2=2\left(13\dfrac{1}{2}\times9\right)=2(13.5\times9)=45~\textup{ft}.[/tex]
Now, we will be using the UNITARY method.
Cost of sand for building rectangular-sand box with perimeter 30ft = $228.
So, cost of sand for building rectangular-sand box with perimeter 1 ft will be
[tex]\$\dfrac{228}{30}.[/tex]
Therefore, the cost of sand for building rectangular-sand box with perimeter 45 ft is given by
[tex]\$\dfrac{228}{30}\times45=\$342.[/tex]
Thus, the required cost of the sand is $342.
Option (C) is CORRECT.
Answer:
A. $513
Step-by-step explanation:
Find the area of the boxes by multiplying the sides.
The first box is 54 ft sq.
The second box is 121.5 ft sq.
So
[tex]\\\frac{54}{121.5} =\frac{228}{x}[/tex]
cross mult.
27702 = 54x
513 = x
