**Question 16**:

State the first two common multiples of 3, 5 and 6.

*Multiples of 3 = 3, 6, 9, 12, 15, 18, 21, 24, 27,*

**Solution**:**30**, 33, 36, 39, 42, 45, 48, 51, 54, 57,

**60**, …

Multiples of 5 = 5, 10, 15, 20, 25,

**30**, 35, 40, 45, 50, 55,

**60**, …

Multiples of 6 = 6, 12, 18, 24,

**30**, 36, 42, 48, 54,

**60**, …

The first two common multiples of 3, 5 and 6 are 30 and 60.

**Question 17**:

Find the lowest common multiple (LCM) of 4, 8 and 24.

**Solution**:**Question 18**:

Find the lowest common multiple (LCM) of 8, 12 and 15.

**Solution**:**Question 19**:

Find the highest common factor (HCF) of 26, 52 and 156.

**Solution**:**Question 20**:

Given that (

*m*+ 5) is the highest common factor of 81 and 108, find the value of

*m*.

**Solution**: