(1) Write all the factors of the following numbers
a. 24
Sol:
24 = 1 × 24,
24 = 2 × 12,
24 = 3 × 8,
24 = 4 × 6,
24 = 6 × 4,
24 = 8 × 3,
24 = 12 × 2,
24 = 24 ×1
So, the factors of 24 are 1, 2, 3, 4, 6, 8, 12 and 24.
b. 15
Sol:
15 = 1 × 15,
15 = 3 × 5,
15 = 5 × 3,
15 = 15 × 1
So, the factors of 15 are 1, 3, 5 and 15.
c. 21
Sol:
21 = 1 × 21,
21 = 3 × 7,
21 = 7 × 3,
21 = 21 × 1
So, the factors are 1, 3, 7 and 21.
d. 27
Sol:
27 = 1 × 27,
27 = 3 × 9,
27 = 9 × 3,
27 = 27 × 1
So, the factors are 1, 3, 9 and 27.
e. 12
Sol:
12 = 1 × 12,
12 = 2 × 6,
12 = 3 × 4,
12 = 4 × 3,
12 = 6 × 2,
12 = 12 × 1
So, the factors are 1, 2, 3, 4, 6 and 12.
f. 20
Sol:
20 = 1 × 20,
20 = 2 × 10,
20 = 4 × 5,
20 = 5 × 4,
20 = 10 × 2,
20 = 20 × 1
So, the factors are 1, 2, 4, 5, 10 and 20.
g. 18
Sol:
18 = 1 × 18,
18 = 2 × 9,
18 = 3 × 6,
18 = 6 × 3,
18 = 9 × 2,
18 = 18 × 1
So, the factors are 1, 2, 3, 6, 9 and 18.
h. 23
Sol:
23 = 1 × 23,
23 = 23 × 1
So, factors of 23 are 1 and 23.
i. 36
Sol:
36 = 1 × 36,
36 = 2 × 18,
36 = 3 × 12,
36 = 4 × 9,
36 = 6 × 6,
36 = 9 × 4,
36 = 12 × 3,
36 = 18 × 2,
36 = 36 × 1
So, factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18 and 36.