GCF (HCF) of 15 and 10

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What is the Greatest Common Divisor of 15 and 10?

Answer

GCF (HCF) of 15 and 10 is
5

Common factors: 1, 5

5 divides both: 15 ÷ 5 = 3, 10 ÷ 5 = 2 — and 3 and 2 share no factor but 1, so no larger number divides both.

15 = 3 × 5

10 = 2 × 5

Prime1510Lowest power
2—2—
33——
5555

— = 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 10?

GCF (HCF) of 15 and 10 is 5

How to find the GCF of 15 and 10?

You can find the GCF of 15 and 10 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 15 and 10 is 5.

What prime factors do 15 and 10 share?

The prime factorizations of 15 and 10 have 5 in common, and multiplying those shared primes gives 5 — exactly the greatest common factor.

How does the GCF reduce the fraction 15/10?

Divide the numerator and the denominator by the GCF 5: 15 ÷ 5 = 3 and 10 ÷ 5 = 2. So 15/10 in lowest terms is 3/2.