GCF (HCF) of 100 and 245

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What is the Greatest Common Divisor of 100 and 245?

Answer

GCF (HCF) of 100 and 245 is
5

Common factors: 1, 5

5 divides both: 100 ÷ 5 = 20, 245 ÷ 5 = 49 — and 20 and 49 share no factor but 1, so no larger number divides both.

100 = 22 × 52

245 = 5 × 72

Prime100245Lowest power
222——
55255
7—72—

— = 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 245?

GCF (HCF) of 100 and 245 is 5

How to find the GCF of 100 and 245?

You can find the GCF of 100 and 245 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 100 and 245 is 5.

What prime factors do 100 and 245 share?

The prime factorizations of 100 and 245 have 5 in common, and multiplying those shared primes gives 5 — exactly the greatest common factor.

How does the GCF reduce the fraction 100/245?

Divide the numerator and the denominator by the GCF 5: 100 ÷ 5 = 20 and 245 ÷ 5 = 49. So 100/245 in lowest terms is 20/49.