Answer:
681 square inches
Explanation:
The surface area of a rectangular prism of dimensions L, W, and H is given by ...
A = 2(LW +H(L+W))
The surface area of the given box is ...
A = 2(12·3 +18.25(12 +3)) = 2(36 +273.75) = 619.5 . . . square inches
The amount of wrapping paper required is 10% more than this value, so is ...
paper required = (1 +.10)(619.5) = 681.45 ≈ 681 . . . square inches