Problem Solving

A rectangular box (20 inches long, 8 inches width, 2 inches height) that is to be completely wrapped with paper. If a single sheet of paper is to be used without patching, then the dimensions of the paper could be
(A) 17 in by 25 in
(B) 21 in by 24 in
(C) 24 in by 12 in
(D) 24 in by 14 in
(E) 26 in by 14 in

dabulaila wrote:A rectangular box (20 inches long, 8 inches width, 2 inches height) that is to be completely wrapped with paper. If a single sheet of paper is to be used without patching, then the dimensions of the paper could be
(A) 17 in by 25 in
(B) 21 in by 24 in
(C) 24 in by 12 in
(D) 24 in by 14 in
(E) 26 in by 14 in

Are you sure the answer is D? What is the source of the question?
For the paper to wrap the box, the surface area of box should be less than or equal to the surface area of paper. Only B satisfies that.

sorry ,, it was my mistake, the answer is B as u said, but how did u come to the answer?

The surface area of a rectangular box with dimension L, W and H is 2(LW+WH+HL) = 2(160+16+40) = 432

(A) 17*25 = 425
(B) 21*24 = 504
(C) 24*12 = 288
(D) 24*4 = 336
(E) 26*14 = 364

Only B can cover the box since the surface area of box is less. In all other cases, the paper will fall short.

thxxx