Examples
Example 1: Find the HCF of 12, 30 and 72.
Solution:
Factors of 12: 2, 2, 3
Factors of 30: 2, 3, 5
Factors of 72: 2, 2, 2, 3, 3
Common prime factors = 2, 3
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(12, 30, 72) = 6.
Example 2: Find the HCF of 50, 65 and 80.
Solution:
Factors of 50: 2, 5, 5
Factors of 65: 5, 13
Factors of 80: 2, 2, 2, 2, 5
Common prime factors = 5
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(50, 65, 80) = 5.
Example 3: Find the HCF of 36, 54 and 72.
Solution:
Factors of 36: 2, 2, 3, 3
Factors of 54: 2, 3, 3, 3
Factors of 72: 2, 2, 2, 3, 3
Common prime factors = 2, 3, 3
HCF: Take only common prime factors and multiply them to get the HCF.
Therefore, HCF(36, 54, 72) = 19.
Exercise
1. HCF(32,48,64) = 16
2. HCF(63,84,105) = 21
3. HCF(45,63,81) = 9
4. HCF(32, 48, 96) = 96
5. HCF(24, 68, 10) = 2
6. HCF(16, 24, 32) = 8
7. HCF(20, 40, 60) = 20
8. HCF(18, 27, 45) = 9
9. HCF(27, 45, 72) = 9
10. HCF(24, 40, 56) = 8