Write all the factors of the following numbers : 

(a) 24           (b) 15            (c)21

(d) 27           (e) 12            (f) 20

(g) 18           (h) 23            (i) 36

The numbers that are multiplied together to produce the original number are known as factors. 

(a) 24 

Product of 24 can be written as 

$24=1\times 24, 24=2\times 12, 24= 3\times 8, 24=4\times 6$

So factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24.

(b) 15

Product of 15 can be written as 

$15=1\times 15, 15=3\times 5$

So factors of 15 are 1, 3, 5, and 15.

(c) 21

Product of 21 can be written as 

$21=1\times 21, 21=3\times 7$

So factors of 21 are 1, 3, 7, and 21.

(d) 27

Product of 27 can be written as 

$27=1\times 27, 27=3\times 9$

So factors of 27 are 1, 3, 9, and 27.

(e) 12

Product of 12 can be written as 

$12=1\times 12, 12=2\times 6, 12= 3\times 4$

So factors of 12 are 1, 2, 3, 4, and 12.

(f) 20

Product of 20 can be written as 

$20=1\times 20, 20=2\times 10, 20= 4\times 5$

So factors of 20 are 1, 2, 4, 5, and 20.

(g) 18

Product of 18 can be written as 

$18=1\times 18, 18=2\times 9, 18=3\times 6,$

So factors of 18 are 1, 2, 3, 6, 9 and 18.

(h) 23

Product of 23 can be written as 

$23=1\times 23$

So factors of 23 are 1, and 23.

(i) 36

Product of 36 can be written as 

$36=1\times 36, 36=2\times 18, 36=3\times 12, 36=4\times 9, 36=6\times 6$

So factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18 and 36.