Examples
Example 1: Find the LCM of 35 and 15.
Solution:
Prime factors of 35 = 5, 7
Prime factors of 15 = 3, 5
Write these prime factors into the venn diagram for each number.
Multiply each prime factor in the venn diagram to find the LCM.
Therefore, LCM(35, 15) = 105.
Example 2: Find the LCM of 8 and 10.
Solution:
Prime factors of 8 = 2, 2, 2
Prime factors of 10 = 2, 5
Write these prime factors into the venn diagram for each number.
Multiply each prime factor in the venn diagram to find the LCM.
Therefore, LCM(8, 10) = 40.
Example 3: Find the LCM of 60 and 120.
Solution:
Prime factors of 60 = 2, 2, 3, 5
Prime factors of 120 = 2, 2, 2, 3, 5
Write these prime factors into the venn diagram for each number.
Multiply each prime factor in the venn diagram to find the LCM.
Therefore, LCM(60, 120) = 120.
Exercise
1. LCM(15,25) = 75
2. LCM(33,44) = 132
3. LCM(27,36) = 108
4. LCM(10,15) = 30
5. LCM(9, 12) = 36
6. LCM(30,40) = 120
7. LCM(20, 80) = 80
8. LCM(24, 36) = 72
9. LCM(11, 15) = 165
10. LCM(36, 45) = 180