The GCF of 3 and 25 is 1. The LCM of 3 and 25 is 75.
3 and 25 share no common factor except 1, so they are coprime (relatively prime). When two numbers are coprime their LCM is simply their product: 3 × 25 = 75.
Factors of 3: 1, 3.
Factors of 25: 1, 5, 25.
Common factors: 1. The greatest of these is 1.
3 = 3 (prime)
25 = 5 × 5
GCF: multiply the prime factors both numbers share: there are none, so the GCF is 1.
LCM: multiply every prime the maximum number of times it appears in either number: 3 × 5 × 5 = 75.
Divide the larger number by the smaller and repeat with the remainder until it is 0. The last non-zero remainder is the GCF.
The last non-zero remainder is 1, so GCF(3, 25) = 1.
Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, ...
Multiples of 25: 25, 50, 75, 100, ...
The first number in both lists is 75.
1 × 75 = 75 = 3 × 25. This always holds for two numbers, so you can find the LCM as (3 × 25) ÷ 1 = 75.
3/25 is already in lowest terms because the GCF of 3 and 25 is 1.
| Numbers | GCF | LCM |
|---|---|---|
| 2 and 3 | 1 | 6 |
| 3 and 4 | 1 | 12 |
| 3 and 5 | 1 | 15 |
| 3 and 6 | 3 | 6 |
| 3 and 7 | 1 | 21 |
| 3 and 8 | 1 | 24 |
| 2 and 25 | 1 | 50 |
| 4 and 25 | 1 | 100 |
| 5 and 25 | 5 | 25 |
| 6 and 25 | 1 | 150 |
| 7 and 25 | 1 | 175 |
| 8 and 25 | 1 | 200 |
See also: factors of 3 · factors of 25 · 3/25 as a decimal.
Different numbers? Use the GCF and LCM calculator (any amount of numbers) or browse all GCF and LCM pairs.