(c) (d) Write down all the factors of 20. Write down the first five multiples of 13. Write down all the factors of 36.

Sure, let's go through each of the questions one by one.<br /><br />### 1. Write down all the factors of 20.<br /><br />Factors are numbers that divide another number exactly without leaving a remainder. For 20, we need to find all the numbers that divide 20 exactly.<br /><br />- 1 (since 20 ÷ 1 = 20)<br />- 2 (since 20 ÷ 2 = 10)<br />- 4 (since 20 ÷ 4 = 5)<br />- 5 (since 20 ÷ 5 = 4)<br />- 10 (since 20 ÷ 10 = 2)<br />- 20 (since 20 ÷ 20 = 1)<br /><br />So, the factors of 20 are: **1, 2, 4, 5, 10,**.<br /><br />### 2. Write down the first five multiples of 13.<br /><br />Multiples of a number are obtained by multiplying that number by any integer. For 13, we need to find the first five multiples.<br /><br />- 13 × 1 = 13<br />- 13 × 2 = 26<br />- 13 × 3 = 39<br />- 13 × 4 = 52<br />- 13 × 5 = 65<br /><br />So, the first five multiples of 13 are: **13, 26, 39, 52, 65**.<br /><br />### 3. Write down all the factors of 36.<br /><br />Again, factors are numbers that divide another number exactly without leaving a remainder. For 36, we need to find all the numbers that divide 36 exactly.<br /><br />- 1 (since 36 ÷ 1 = 36)<br />- 2 (since 36 ÷ 2 = 18)<br />- 3 (since 36 ÷ 3 = 12)<br />- 4 (since 36 ÷ 4 = 9)<br />- 6 (since 36 ÷ 6 = 6)<br />- 9 (since 36 ÷ 9 = 4)<br />- 12 (since 36 ÷ 12 = 3)<br />- 18 (since 36 ÷ 18 = 2)<br />- 36 (since 36 ÷ 36 = 1)<br /><br />So, the factors of 36 are: **1, 2, 3, 4, 6, 9, 12, 18, 36**.<br /><br />I hope this helps! If you have any more questions, feel free to ask.