Given:
Length of a box is 9 inches, width is 2 inches and height is 1.5 inches.
The cost of silver coating is $2.50 per sq. inches.
To find:
The total cost of silver coating for the box.
Solution:
The total surface area of a cuboid is
[tex]A=2(lb+bh+hl)[/tex]
Where, l is length, b is breadth and h is height.
Putting [tex]l=9,b=2,h=1.5[/tex], we get
[tex]A=2(9\times 2+2\times 1.5+1.5\times 9)[/tex]
[tex]A=2(18+3+13.5)[/tex]
[tex]A=2(34.5)[/tex]
[tex]A=69[/tex]
So, the total surface area of the box is 69 square inches.
Cost of silver coating is $2.50 per sq. inches. So, the cost of silver coating for the box is
[tex]Cost=69\times 2.50[/tex]
[tex]Cost=172.50[/tex]
Therefore, the cost of silver coating for the box is $172.50.
