The GCF of 25 and 50 is 25. The LCM of 25 and 50 is 50.
Factors of 25: 1, 5, 25.
Factors of 50: 1, 2, 5, 10, 25, 50.
Common factors: 1, 5 and 25. The greatest of these is 25.
25 = 5 × 5
50 = 2 × 5 × 5
GCF: multiply the prime factors both numbers share: 5 × 5 = 25.
LCM: multiply every prime the maximum number of times it appears in either number: 2 × 5 × 5 = 50.
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 25, so GCF(25, 50) = 25.
Multiples of 25: 25, 50, 75, ...
Multiples of 50: 50, 100, ...
The first number in both lists is 50.
25 × 50 = 1,250 = 25 × 50. This always holds for two numbers, so you can find the LCM as (25 × 50) ÷ 25 = 50.
Divide the top and bottom by the GCF 25: 25/50 = 1/2.
| Numbers | GCF | LCM |
|---|---|---|
| 2 and 25 | 1 | 50 |
| 3 and 25 | 1 | 75 |
| 4 and 25 | 1 | 100 |
| 5 and 25 | 5 | 25 |
| 6 and 25 | 1 | 150 |
| 7 and 25 | 1 | 175 |
| 2 and 50 | 2 | 50 |
| 3 and 50 | 1 | 150 |
| 4 and 50 | 2 | 100 |
| 5 and 50 | 5 | 50 |
| 6 and 50 | 2 | 150 |
| 7 and 50 | 1 | 350 |
See also: factors of 25 · factors of 50.
Different numbers? Use the GCF and LCM calculator (any amount of numbers) or browse all GCF and LCM pairs.