### Examples

**Example 1:** Find the LCM of 4, 7 and 14.

**Solution:**

Prime factors of 4 = 2, 2

Prime factors of 7 = 7

Prime factors of 14 = 2, 7

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(4, 7, 14) = 28.
**Example 2:** Find the LCM of 3, 6 and 9.

**Solution:**

Prime factors of 3 = 3

Prime factors of 6 = 2, 3

Prime factors of 9 = 3, 3

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(3, 6, 9) = 18.
**Example 3:** Find the LCM of 6, 7 and 21.

**Solution:**

Prime factors of 6 = 2, 3

Prime factors of 7 = 7

Prime factors of 21 = 3, 7

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(6, 7, 21) = 42.

### Exercise

**1.** LCM(12,15,20) = 60

**2.** LCM(18,24,36) = 72

**3.** LCM(30,40,45) = 360

**4.** LCM(10,18,20) = 180

**5.** LCM(10,12,15) = 60

**6.** LCM(8, 4, 6) = 24

**7.** LCM(3,7,14) = 42

**8.** LCM(15, 25, 35) = 525

**9.** LCM(10,18,20) = 180

**10.** LCM(5,9,18) = 90