Examples
Example 1: Find the HCF of 15 and 20.
Solution:
Prime factorization of 15: 15 = 3, 5
Prime factorization of 20: 20 = 2, 2, 5
Take the common prime factors and multiply them together to get HCF.
Therefore, HCF(15, 20) = 5.
Example 2: Find the HCF of 18 and 24.
Solution:
Prime factorization of 18: 18 = 2, 3, 3
Prime factorization of 24: 24 = 2, 2, 2, 3
Take the common prime factors and multiply them together to get HCF.
Therefore, HCF(18, 24) = 6.
Example 3: Find the HCF of 8 and 12.
Solution:
Prime factorization of 8: 8 = 2, 2, 2
Prime factorization of 12: 12 = 2, 2, 3
Take the common prime factors and multiply them together to get HCF.
Therefore, HCF(8, 12) = 4.
Exercise
1. HCF(3,9,18) = 3
2. HCF(50,70,90) = 10
3. HCF(63,84,105) = 21
4. HCF(15,25,35) = 5
5. HCF(16,24,32) = 8
6. HCF(5,10,15) = 5
7. HCF(9,12,15) = 3
8. HCF(6,9,15,18) = 3
9. HCF(20,60,80) = 20
10. HCF(20,35,40,50) = 5