UPSC PYQPrelims 2025

Civil Services Examination · प्रश्न 28

There are n sets of numbers each having only three positive integers with LCM equal to 1001 and HCF equal to 1. What is the value of n?

  1. 6
  2. 7
  3. 8
  4. More than 8
उत्तर देखें और व्याख्या

उत्तर: (D) More than 8

व्याख्या

1001 = 7 × 11 × 13. Many triples of divisors have LCM 1001 and HCF 1 (e.g. {1, 7, 143}, {7, 11, 13}, {1, 1001, x}, {7, 11, 91}...), well over 8. (Answer as per the official UPSC answer key.)