Examples
Example 1: Find the HCF of 36 and 72.
Solution:
Factors of 36: 2, 2, 3, 3
Factors of 72: 2, 2, 2, 3, 3
Common prime factors = 2, 2, 3, 3
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(36, 72) = 36.
Example 2: Find the HCF of 12 and 30.
Solution:
Factors of 12: 2, 2, 3
Factors of 30: 2, 3, 5
Common prime factors = 2, 3
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(12, 30) = 6.
Example 3: Find the HCF of 60 and 72.
Solution:
Factors of 60: 2, 2, 3, 5
Factors of 72: 2, 2, 2, 3, 3
Common prime factors = 2, 2, 3
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(60, 72) = 12.
Exercise
1. HCF(63,81) = 9
2. HCF(35,70) = 35
3. HCF(54,72) = 18
4. HCF(16,40) = 8
5. HCF(24,36) = 12
6. HCF(24,60) = 12
7. HCF(36,63) = 9
8. HCF(30,50) = 10
9. HCF(75,45) = 15
10. HCF(18,24) = 6