GCF and LCM of 3 and 5
The greatest common factor and least common multiple of 3 and 5.
GCF of 3 and 5
1
LCM of 3 and 5
15
How it works
Break each number into its prime factors:
- 3 = 3
- 5 = 5
The GCF (1) multiplies the primes both share, at the lowest power each appears. The LCM (15) multiplies every prime that appears in either number, at the highest power — which is also 3 × 5 ÷ 1 = 15.
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Need a different pair? The LCM & GCF calculator computes the GCF and LCM for any two numbers.
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Frequently asked questions
What is the GCF of 3 and 5?+
The greatest common factor (GCF) of 3 and 5 is 1 — the largest number that divides both 3 and 5 with no remainder.
What is the LCM of 3 and 5?+
The least common multiple (LCM) of 3 and 5 is 15 — the smallest number that both 3 and 5 divide into. It equals 3 × 5 ÷ GCF = 15 ÷ 1 = 15.