Question

Difficulty: EasyAlgebraic Equations and Systems in Data Sufficiency

If xx and yy are real numbers, what is the value of x+yx + y?

(1) 3x+3y=123x + 3y = 12
(2) xy=2x - y = 2

  1. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.Answer
  2. B
    Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
  3. C
    BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
  4. D
    EACH statement ALONE is sufficient.
  5. E
    Statements (1) and (2) TOGETHER are NOT sufficient.

Answer

Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
The correct option correctly identifies that Statement (1) alone is sufficient because dividing 3x+3y=123x + 3y = 12 by 3 yields x+y=4x + y = 4, directly answering the question without needing to solve for xx and yy individually. Statement (2) alone leaves x+yx + y undetermined.

Step-by-Step Solution

1
Analyze the target expression in the question stem.
The target to find is a single value for x+yx + y.
Rephrasing the question stem clarifies what exact numerical value or algebraic combination is required.
2
Evaluate Statement (1) independently: 3x+3y=123x + 3y = 12.
Factor out 3 to get 3(x+y)=123(x + y) = 12, then divide by 3 to obtain x+y=4x + y = 4.
Statement (1) gives a unique value for the target expression x+yx + y, so Statement (1) alone is sufficient.
3
Evaluate Statement (2) independently: xy=2x - y = 2.
If x=3x = 3 and y=1y = 1, then xy=2x - y = 2 and x+y=4x + y = 4. If x=4x = 4 and y=2y = 2, then xy=2x - y = 2 and x+y=6x + y = 6.
Multiple values for x+yx + y are possible, so Statement (2) alone is not sufficient.

Key Concept

Question Stem Rephrasing and Linear Expression Combination
Estimated Time:1m 0s
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