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There is a question followed by two statements I and II :
Question :
If x and y are integers, can we find |x- y| uniquely?
I. x2 + y2 =25
II. x2-y2 = 7
Which one of the following options is correct?
Explanation
To determine if |x - y| can be found uniquely, we evaluate the statements provided:
Statement I: x2 + y2 = 25. Since x and y are integers, possible pairs (x, y) include (5, 0) and (3, 4). For (5, 0), |x - y| = 5. For (3, 4), |x - y| = 1. Since multiple values are possible, Statement I alone is not sufficient.
Statement II: x2 - y2 = 7. This can be factored as (x - y)(x + y) = 7. Since x and y are integers, the factors of 7 are (1, 7), (7, 1), (-1, -7), and (-7, -1).
If (x - y) = 1 and (x + y) = 7, then x = 4, y = 3, and |x - y| = 1.
If (x - y) = 7 and (x + y) = 1, then x = 4, y = -3, and |x - y| = 7.
Since |x - y| can be 1 or 7, Statement II alone is not sufficient.
Combined: Solving both equations simultaneously gives x2 = 16 and y2 = 9, resulting in x = ±4 and y = ±3. The possible values for |x - y| remain 1 and 7. Because the value is not unique, the question cannot be answered even using both statements.
SIMILAR QUESTIONS
Consider the following statements : Statement I : Some rare earth elements are used in the manufacture of flat television screens and computer monitors. Statement II : Some rare earth elements have phosphorescent properties. Which one of the following is correct in respect of the above statements?
Directions (Q. 140-143): The following questions are based on the Table given below. You are to match List-I with List-II, List-III, and List-IV, and select the correct answer using the code given below:
| List-I (Material) | List-II (Property/Process) | List-III (Structure/Composition) | List-IV (Uses/Features) |
|---|---|---|---|
| A. Diamond | 1. Thermosetting polymer | I. Rigid structure | i. Non-conductor |
| B. Graphite | 2. Monomer | II. Sheet-like structure | ii. Ester |
| C. Rayon | 3. Soft | III. Cellulose | iii. Conductor of heat |
| D. Nylon | 4. Viscose process | IV. Soft on heating | iv. Ether |
| E. Carbon fibre | 5. Synthetic fibre | V. Unreactive | v. Silk-like thread |
| F. Polyvinyl chloride | 6. High strength | VI. Corrosion resistant | vi. Spacecraft |
| G. Terylene | 7. Thermoplastic | VII. Melts instead of burning | vii. Chlorine atom replaces hydrogen |
| H. Bakelite | 8. Polyester fibre | VIII. Ethylene glycol | viii. Cross-linked |
| 9. Hardest natural substance | IX. Phenol and formaldehyde | ix. Terephthalic acid |
140. Which of the following matches is correct?