### Examples

**Example 1:** Find the HCF of 24 and 36.

**Solution:**

Prime factorization of 24: 24 = 2, 2, 2, 3

Prime factorization of 36: 36 = 2, 2, 3, 3

Take the common prime factors and multiply them together to get HCF.

Therefore, HCF(24, 36) = 12.
**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 36 and 45.

**Solution:**

Prime factorization of 36: 36 = 2, 2, 3, 3

Prime factorization of 45: 45 = 3, 3, 5

Take the common prime factors and multiply them together to get HCF.

Therefore, HCF(36, 45) = 9.

### Exercise

**1.** HCF(18,27) = 9

**2.** HCF(45,60) = 15

**3.** HCF(32,48) = 16

**4.** HCF(84,105) = 21

**5.** HCF(72, 90) = 18

**6.** HCF(60,72) = 12

**7.** HCF(56,84) = 28

**8.** HCF(17,89) = 1

**9.** HCF(315,495) = 45

**10.** HCF(60,20) = 20