Is the perimeter of a given rectangle greater than 8 inches? (1) The two…

2023

Is the perimeter of a given rectangle greater than 8 inches?

(1) The two shorter sides of the rectangle are 2 inches long.

(2) The length of the rectangle is 2 inches greater than the width of the rectangle.

  1. A.

    Statement (1) ALONE is sufficient, but statement (2) is not sufficient

  2. B.

    Statement (2) ALONE is sufficient, but statement (1) is not sufficient

  3. C.

    BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient

  4. D.

    EACH statement ALONE is sufficient.

Show answer & explanation

Correct answer: A

Concept

In a Data Sufficiency question, a statement is sufficient only if it lets you answer the Yes/No question with the same certain answer for every case consistent with that statement. For a rectangle, perimeter = 2 × (length + width). A Yes/No threshold question can sometimes be settled even by a partial or relational constraint, as long as it forces the sum (length + width) to always stay on one side of the threshold.

Application

  • Statement (1) alone:

    1. The two shorter sides are 2 inches long, so width = 2 inches.

    2. Because these are explicitly the SHORTER sides, the length must be strictly greater than the width: length > 2 inches.

    3. Perimeter = 2 × (length + width) = 2 × (length + 2). Since length > 2, perimeter > 2 × (2 + 2) = 8 inches for every valid rectangle. The answer is always “Yes” → sufficient.

  • Statement (2) alone:

    1. Let width = w. Then length = w + 2.

    2. Perimeter = 2 × (length + width) = 2 × (w + 2 + w) = 4w + 4.

    3. w is not fixed by this statement: if w = 0.5, perimeter = 6 inches (“No”); if w = 10, perimeter = 44 inches (“Yes”). Different valid values give different Yes/No answers, so this statement alone is NOT sufficient.

Cross-check

Plug back into Statement (1): width = 2, length = 3 (valid since 3 > 2) gives perimeter = 2 × 5 = 10 > 8 (“Yes”). width = 2, length = 2.001 gives perimeter = 2 × 4.001 = 8.002 > 8 (“Yes”). Every valid case agrees.

For Statement (2), the two test values (w = 0.5 giving “No” and w = 10 giving “Yes”) confirm it gives conflicting answers and is therefore insufficient.

Result

Statement (1) ALONE is sufficient, but Statement (2) is not sufficient.

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