Solutions by everydaycalculation.com

The GCF of 18 and 15 is 3.

- Find the prime factorization of 18

18 = 2 × 3 × 3 - Find the prime factorization of 15

15 = 3 × 5 - To find the GCF, multiply all the prime factors common to both numbers:

Therefore, GCF = 3

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Find hcf of: 36 & 30 54 & 45 6 & 5 90 & 75 126 & 105 36 & 15 18 & 30 54 & 15 18 & 45 90 & 15 18 & 75 126 & 15 18 & 105

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The greatest common factor (GCF) is also known as greatest common divisor (GCD) or highest common factor (HCF).

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