GCF (HCF) of 90 and 210

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What is the Greatest Common Divisor of 90 and 210?

Answer

GCF (HCF) of 90 and 210 is
30

Common factors: 1, 2, 3, 5, 6, 10, 15, 30

30 divides both: 90 ÷ 30 = 3, 210 ÷ 30 = 7 — and 3 and 7 share no factor but 1, so no larger number divides both.

90 = 2 × 32 × 5

210 = 2 × 3 × 5 × 7

Prime90210Lowest power
2222
33233
5555
7—7—

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

GCF = 2 × 3 × 5 = 30

See Also

FAQ

What is the Greatest Common Divisor of 90 and 210?

GCF (HCF) of 90 and 210 is 30

How to find the GCF of 90 and 210?

You can find the GCF of 90 and 210 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 90 and 210 is 30.

What prime factors do 90 and 210 share?

The prime factorizations of 90 and 210 have 2 × 3 × 5 in common, and multiplying those shared primes gives 30 — exactly the greatest common factor.

How does the GCF reduce the fraction 90/210?

Divide the numerator and the denominator by the GCF 30: 90 ÷ 30 = 3 and 210 ÷ 30 = 7. So 90/210 in lowest terms is 3/7.