GCF (HCF) of 100 and 105

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What is the Greatest Common Divisor of 100 and 105?

Answer

GCF (HCF) of 100 and 105 is
5

Common factors: 1, 5

5 divides both: 100 ÷ 5 = 20, 105 ÷ 5 = 21 — and 20 and 21 share no factor but 1, so no larger number divides both.

100 = 22 × 52

105 = 3 × 5 × 7

Prime100105Lowest power
222——
3—3—
55255
7—7—

— = power 0: the prime is not a factor of this number, so it cannot be in the GCF.

GCF = 5

See Also

FAQ

What is the Greatest Common Divisor of 100 and 105?

GCF (HCF) of 100 and 105 is 5

How to find the GCF of 100 and 105?

You can find the GCF of 100 and 105 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 100 and 105 is 5.

What prime factors do 100 and 105 share?

The prime factorizations of 100 and 105 have 5 in common, and multiplying those shared primes gives 5 — exactly the greatest common factor.

How does the GCF reduce the fraction 100/105?

Divide the numerator and the denominator by the GCF 5: 100 ÷ 5 = 20 and 105 ÷ 5 = 21. So 100/105 in lowest terms is 20/21.