Examples
Example 1: Find the LCM of 12 and 18.
Solution:
Prime factorization of 12: 12 = 2, 2, 3
Prime factorization of 18: 18 = 2, 3, 3
Take the common factors once and remaining unique factors.
Multiply them together to get LCM.
Therefore, LCM(12, 18) = 36.
Example 2: Find the LCM of 15 and 25.
Solution:
Prime factorization of 15: 15 = 3, 5
Prime factorization of 25: 25 = 5, 5
Take the common factors once and remaining unique factors.
Multiply them together to get LCM.
Therefore, LCM(15, 25) = 75.
Example 3: Find the LCM of 20 and 30.
Solution:
Prime factorization of 20: 20 = 2, 2, 5
Prime factorization of 30: 30 = 2, 3, 5
Take the common factors once and remaining unique factors.
Multiply them together to get LCM.
Therefore, LCM(20, 30) = 60.
Exercise
1. LCM(24,36,48) = 144
2. LCM(6,9,12,15) = 180
3. LCM(24,36) = 72
4. LCM(15,25,35) = 525
5. LCM(18,24,36) = 72
6. LCM(15,20,25,30) = 300
7. LCM(8,12) = 24
8. LCM(21,28) = 84
9. LCM(9,12,15) = 180
10. LCM(20,30,40) = 120