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Home Aptitude Problems on H.C.F and L.C.M See What Others Are Saying!
  • Question
  • The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is:


  • Options
  • A. 1
  • B. 2
  • C. 3
  • D. 4

  • Correct Answer


  • Explanation
    Let the numbers 13 a and 13 b

    Then, 13a x 13b = 2028

    ab = 12.

    Now, the co-primes with product 12 are (1, 12) and (3, 4).

    [Note: Two integers a and b are said to be coprime or relatively prime if they have no common positive factor other than 1 or, equivalently, if their greatest common divisor is 1 ]

    So, the required numbers are (13 x 1, 13 x 12) and (13 x 3, 13 x 4).

    Clearly, there are 2 such pairs.

  • Tags: AIEEE, Bank Exams, CAT, GRE, TOEFL, Bank Clerk, Bank PO, Analyst

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