Question

Write out the prime factor of the following numbers.
a. 15
b. 21
c. 38
d. 42

Answer 1

A: 5 and 3

B: 7 and 3

C: 19 and 2

D: 2 and 3 and 7

Answer 2

Answer with explanation:

We know that the prime factorization of a number "n" is given by:

`n=p_1\cdot p_2\cdot p_3\cdot p_4`

where
`p_i's` are distinct prime.

(a)

`15`

It could be written as:

`15=3* 5`

Hence, the prime factors of this number are:

3 and 5.

(b)

21

It could be written as:

`21=3* 7`

Hence, the prime factors of this number are:

3 and 7.

(c)

38

It could be written as:

`38=2* 19`

Hence, the prime factors of this number are:

2 and 19.

(d)

42

It could be written as:

`42=2* 3* 7`

Hence, the prime factors of this number are:

2 , 3 and 7.