LCM and HCF


  1. Find the HCF of 4/5 and 7/15?











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    HCF of fractions = (HCF of numerators) / (LCM of denominators)

    Correct Option: C

    We know that,
    HCF of fractions = (HCF of numerators) / (LCM of denominators)
    ∴ Required HCF = (HCF of 4 and 7) / (LCM of 5 and 15)
    =1/15


  1. Consider the number between 300 and 400 which when divided by 12, 18 and 36 leaves 4 as remainder in each case. what is the sum of the number ?









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    LCM of (12,18, 36) = 36
    ∴ A number greater than 300 on dividing by 36 leaves a remainder 4 = (36 x 9) + 4 = 328
    Next numbe r = 328 + 36 = 364

    Correct Option: B

    LCM of (12,18, 36) = 36
    ∴ A number greater than 300 on dividing by 36 leaves a remainder 4 = (36 x 9) + 4 = 328
    Next numbe r = 328 + 36 = 364
    ∴ Sum of number = 328 + 364 = 692



  1. Find the HCF of 132, 204 and 228.









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    132 = 2 x 2 x 3 x 11
    240 = 2 x 2 x 2 x 2 x 3 x 5
    228 = 2 x 2 x 3 x 19

    Correct Option: A

    132 = 2 x 2 x 3 x 11
    240 = 2 x 2 x 2 x 2 x 3 x 5
    228 = 2 x 2 x 3 x 19

    Hence, HCF of 132, 204 and 228 = 2 x 2 x 3 = 12


  1. What is the greatest number which divides 390, 480 and 620 so as to leave the same remainder in each case ?









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    The HCF of [(480 - 390), (620 - 480), (620 - 390)]

    Correct Option: B

    The HCF of [(480 - 390), (620 - 480), (620 - 390)]
    = HCF of 90, 140, 230 = 10



  1. Find the HCF of 1/2, 3/4, and 4/5?











  1. View Hint View Answer Discuss in Forum

    Required HCF = (HCF of numerators) / (LCM of denominators)

    Correct Option: A

    Required HCF = (HCF of numerators) / (LCM of denominators)
    = (HCF of 1, 3 and 4) / (LCM of 2, 4, and 5)
    = 1/20