Data Sufficiency

Gmat_mission wrote:A rectangular field is 3.2 yards long. What is the area of the field in square yards?

(1) A fence marking the boundary is 11.2 yards in length.
(2) The distance between the diagonally opposite corners of the rectangular field is 4 yards.

[spoiler]OA=D[/spoiler].

Can any expert clarify this questions for me? I don't know how to conclude that the correct answer is D. <i class="em em-neutral_face"></i>

To get the area of the rectangular field, we need its length and width.

We know that area of a rectangle = length* width

We are given that Length = 3.2 yards.

If we get the value of width, we get the answer.

Let's take each statement one by one.

(1) A fence marking the boundary is 11.2 yards in length.

=> Perimeter of the rectangular field = 11.2 yards

=> 2*(length + width) =11.2

By plugging-in the value of length = 3.2, we get 2*(3.2 + width) = 11.2

=> Width = 2.4 yards

Sufficient.

(2) The distance between the diagonally opposite corners of the rectangular field is 4 yards.

Diagonal of a rectangle = √(Length^2 + Width^2)

4 = √(3.2^2 + Width^2)

14 = (3.2^2 + Width^2)

We can get the unique value of width. There is no need to calculate the answer as this is a DS question and we only need to be sure that we get the unique answer. Sufficient.

The correct answer: D

Hope this helps!

-Jay
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