GCF and LCM of 15 and 25
The greatest common factor and least common multiple of 15 and 25.
GCF of 15 and 25
5
LCM of 15 and 25
75
How it works
Break each number into its prime factors:
- 15 = 3 × 5
- 25 = 5²
The GCF (5) multiplies the primes both share, at the lowest power each appears. The LCM (75) multiplies every prime that appears in either number, at the highest power — which is also 15 × 25 ÷ 5 = 75.
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Frequently asked questions
What is the GCF of 15 and 25?+
The greatest common factor (GCF) of 15 and 25 is 5 — the largest number that divides both 15 and 25 with no remainder.
What is the LCM of 15 and 25?+
The least common multiple (LCM) of 15 and 25 is 75 — the smallest number that both 15 and 25 divide into. It equals 15 × 25 ÷ GCF = 375 ÷ 5 = 75.