All Exams Test series for 1 year @ ₹349 only
Question

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?

This question was previously asked in
UPSC CAPF 2026 General Ability and Intelligence Question Paper (19-Jul-2026)
The correct answer is

The question cannot be answered even using any of the statements

Statement I: \(x^2+y^2=25\) has integer solutions (x, y) = (0, ±5), (±5, 0), (±3, ±4), (±4, ±3). These give |x − y| values such as 5, 1 and 7 depending on which pair is taken, so the value is not unique. Statement I alone is insufficient.

Statement II: \(x^2-y^2=7\), i.e., \((x-y)(x+y)=7\). The integer factor pairs of 7 give (x, y) = (4, 3), (4, −3), (−4, 3), (−4, −3), yielding |x − y| equal to either 1 or 7 depending on the pair. Statement II alone is also insufficient.

Combining both: solving \(x^2+y^2=25\) and \(x^2-y^2=7\) together gives \(x^2=16,\ y^2=9\), so x = ±4 and y = ±3. All four sign combinations satisfy both equations simultaneously (since only the squares are fixed), giving |x − y| equal to 1 for (4, 3) or (−4, −3), and 7 for (4, −3) or (−4, 3).

Even together, the two statements do not pin down a unique value of |x − y|. Hence, the question cannot be answered even using both statements together.

Was this answer helpful?

Similar Questions

  1. P, Q, R and S are four places. To travel from P to R, one travels via Q and to travel from P to S, one travels via both Q and R. Between P and Q, there are 3 routes; between Q and R, there are 4 routes; and between R and S, there are 5 routes. The time taken to travel through these routes is exhibited on the following chart in hours for a specific vehicle :

    RoutesBetween P and QBetween Q and RBetween R and S
    1212
    231.52
    3422.5
    4-23
    5--3.5

    How many possible routes are there if the journey takes exactly 7 hours?


Important Questions from Quant Based Puzzle

  1. Three years ago, the difference between the age of Ravish and the age of Kailash was 18 years. Three years from today, Ravish will be three times as old as Kailash. What is the present age of Ravish (in years)?

  2. Seven years from now, Anamika will be as old as Malini was 4 years ago. Srinidhi was born 2 years ago. The average age of Anamika, Malini and Srinidhi 10 years from now will be 33 years. What is the present age of Anamika?

  3. An amount of ₹1,003 is to be distributed among A, B and C in the ratio of 11 : 23 : 25. How many rupees would B get more than A?

  4. In an exam of 80 questions, a correct answer gives 1 marks but a wrong answer deducts 1 marks, and if a question in not attempted there is no deduction in marks. If a student attempted only 80% of the question and got 32 marks, then how many questions did he answer correctly?

  5. The ratio of the present ages of Asha and Lata is 5 : 6. If the difference between their ages is 6 years, then what will be Lata’s age after 5 years?

Need Expert Advice?
Upcoming Exams
UPSC CMS
August 02, 2026
IAS Exam
August 21, 2026
UPSC SO Steno
December 12, 2026
Test Series
UPSC CAPF img
UPSC
UPSC CAPF (Assistant Commandants) 2026 Mock Test Series
181 Tests 4 Tests Free
6251 Attempts
4.2(115)
English, Hindi
More Questions from UPSC CAPF

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App