GCF (HCF) of 15 and 35

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What is the Greatest Common Divisor of 15 and 35?

Answer

GCF (HCF) of 15 and 35 is
5

Common factors: 1, 5

5 divides both: 15 ÷ 5 = 3, 35 ÷ 5 = 7 — and 3 and 7 share no factor but 1, so no larger number divides both.

15 = 3 × 5

35 = 5 × 7

Prime1535Lowest power
33——
5555
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 15 and 35?

GCF (HCF) of 15 and 35 is 5

How to find the GCF of 15 and 35?

You can find the GCF of 15 and 35 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 15 and 35 is 5.

What prime factors do 15 and 35 share?

The prime factorizations of 15 and 35 have 5 in common, and multiplying those shared primes gives 5 — exactly the greatest common factor.

How does the GCF reduce the fraction 15/35?

Divide the numerator and the denominator by the GCF 5: 15 ÷ 5 = 3 and 35 ÷ 5 = 7. So 15/35 in lowest terms is 3/7.