New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    HCF and LCM of two numbers are 13 and 455. If one number

    lies between 60 and 70, then the other number lies between
    A 50 and 60 Correct Answer Incorrect Answer
    B 70 and 80 Correct Answer Incorrect Answer
    C 80 and 90 Correct Answer Incorrect Answer
    D 90 and 10 Correct Answer Incorrect Answer

    Solution

    Let the numbers be 13m and 13n.
    13m x 13n = 13 x 455 = 13 x 13 x 35
    Or mn = 35
    The co-prime numbers whose product is 35 are (5,7) and (1,35)
    Hence, the no.s are 13 x 5 and 13 x 7 or 13 x 1 and 13 x 35
    Or 65 and 91 or 13 and 455
    Given that, one them lies between 60 and 70 ie 65,
    Then the other number is 91 which lies between 90 and 100

    Practice Next