Positive and Negative Fractions Analysis

CMAT 2022 · Quantitative Techniques & Data Interpretation · Hard · Algebra

If 1x\frac{1}{x} is a positive fraction and 1y\frac{1}{y} is a negative fraction, then which of the following statements are true? (A) 1x+1y\frac{1}{x} + \frac{1}{y} is positive (B) 1x−1y\frac{1}{x} - \frac{1}{y} is positive (C) x−yxy\frac{x - y}{xy} is negative (D) 1xy\frac{1}{xy} is positive (E) 1x2−1y2\frac{1}{x^2} - \frac{1}{y^2} is positive

Choose the correct answer from the options given below:

  1. A.

    Only (A) & (B) are true

  2. B.

    Only (B) & (C) are true

  3. C.

    Only (D) & (E) are true

  4. D.

    Only (A) & (E) are true

Answer

B

Explanation

Given x>0x > 0 and y<0y < 0.

  • (A) 1x+1y\frac{1}{x} + \frac{1}{y}: Sign depends on absolute values of xx and yy. Not necessarily positive.
  • (B) 1x−1y=pos−(neg)=pos+pos>0\frac{1}{x} - \frac{1}{y} = \text{pos} - (\text{neg}) = \text{pos} + \text{pos} > 0. Always true.
  • (C) x−yxy\frac{x - y}{xy}: x−y>0x - y > 0 (pos) and xy<0xy < 0 (neg), so posneg<0\frac{\text{pos}}{\text{neg}} < 0. Always true.
  • (D) 1xy<0\frac{1}{xy} < 0. False.
  • (E) Sign depends on ∣x∣|x| vs ∣y∣|y|. Not always true. Therefore, only (B) and (C) are true.

Related Algebra questions

Practise this under exam conditions

Sign in to solve it with a live timer, the on-screen CAT calculator, and streak and accuracy tracking across every question you attempt.

Solve in the workspace