GCF (HCF) of 15 and 36

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What is the Greatest Common Divisor of 15 and 36?

Answer

GCF (HCF) of 15 and 36 is
3

Common factors: 1, 3

3 divides both: 15 ÷ 3 = 5, 36 ÷ 3 = 12 — and 5 and 12 share no factor but 1, so no larger number divides both.

15 = 3 × 5

36 = 22 × 32

Prime1536Lowest power
2—22—
33323
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 36?

GCF (HCF) of 15 and 36 is 3

How to find the GCF of 15 and 36?

You can find the GCF of 15 and 36 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 15 and 36 is 3.

What prime factors do 15 and 36 share?

The prime factorizations of 15 and 36 have 3 in common, and multiplying those shared primes gives 3 — exactly the greatest common factor.

How does the GCF reduce the fraction 15/36?

Divide the numerator and the denominator by the GCF 3: 15 ÷ 3 = 5 and 36 ÷ 3 = 12. So 15/36 in lowest terms is 5/12.