GCF (HCF) of 15 and 24

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What is the Greatest Common Divisor of 15 and 24?

Answer

GCF (HCF) of 15 and 24 is
3

Common factors: 1, 3

3 divides both: 15 ÷ 3 = 5, 24 ÷ 3 = 8 — and 5 and 8 share no factor but 1, so no larger number divides both.

15 = 3 × 5

24 = 23 × 3

Prime1524Lowest power
2—23—
3333
55——

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

GCF = 3

See Also

FAQ

What is the Greatest Common Divisor of 15 and 24?

GCF (HCF) of 15 and 24 is 3

How to find the GCF of 15 and 24?

You can find the GCF of 15 and 24 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 15 and 24 is 3.

What prime factors do 15 and 24 share?

The prime factorizations of 15 and 24 have 3 in common, and multiplying those shared primes gives 3 — exactly the greatest common factor.

How does the GCF reduce the fraction 15/24?

Divide the numerator and the denominator by the GCF 3: 15 ÷ 3 = 5 and 24 ÷ 3 = 8. So 15/24 in lowest terms is 5/8.