What are the Highest common factor and Lowest common multiple of 6, 72, 120 ?

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What are the Highest common factor and Lowest common multiple of 6, 72, 120 ?

Answer: B. 6, 360Method: factor each number into primes; HCF is the product of common primes with the smallest exponents, and LCM is the product of all primes with the largest…

  1. A.

    12, 180

  2. B.

    6, 360

  3. C.

    360, 6

  4. D.

    12, 360

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Correct answer: B

Method: factor each number into primes; HCF is the product of common primes with the smallest exponents, and LCM is the product of all primes with the largest exponents.

  • 6 = 2 × 3

  • 72 = 2 × 2 × 2 × 3 × 3 ( = 2^3 × 3^2 )

  • 120 = 2 × 2 × 2 × 3 × 5 ( = 2^3 × 3 × 5 )

HCF calculation: common primes are 2 and 3 with minimum exponents 1 and 1 → HCF = 2 × 3 = 6

LCM calculation: take the highest exponents for each prime: 2^3, 3^2, 5^1 → LCM = 2 × 2 × 2 × 3 × 3 × 5 = 360

Final answer: HCF = 6, LCM = 360

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