If [tex]$A=\{1,2,3,4,5,6,7,8,9\}$[/tex],

[tex]$P=\{x : x \in A \text{ and } x \text{ is odd}\}$[/tex],

[tex]$Q=\{x : x \in A \text{ and } x \text{ is prime}\}$[/tex],

and [tex]$R=\{x : x \in A \text{ and } x \text{ is even}\}$[/tex],

then find the elements of [tex]$P, Q,$[/tex] and [tex]$R$[/tex].



Answer :

Certainly! Let's go through the process of determining the sets [tex]\(P\)[/tex], [tex]\(Q\)[/tex], and [tex]\(R\)[/tex] given the set [tex]\(A\)[/tex].

1. Set [tex]\(A\)[/tex]
[tex]\[ A = \{1, 2, 3, 4, 5, 6, 7, 8, 9\} \][/tex]

2. Set [tex]\(P\)[/tex]: elements of [tex]\(A\)[/tex] that are odd numbers

A number is odd if it is not divisible by 2. We check each element of [tex]\(A\)[/tex] to see if it is odd:
- 1 is odd
- 2 is not odd
- 3 is odd
- 4 is not odd
- 5 is odd
- 6 is not odd
- 7 is odd
- 8 is not odd
- 9 is odd

Thus, the odd numbers in [tex]\(A\)[/tex] are:
[tex]\[ P = \{1, 3, 5, 7, 9\} \][/tex]

3. Set [tex]\(Q\)[/tex]: elements of [tex]\(A\)[/tex] that are prime numbers

A prime number is a number greater than 1 that has no positive divisors other than 1 and itself. We check each element of [tex]\(A\)[/tex] to determine if it is prime:
- 1 is not prime
- 2 is prime
- 3 is prime
- 4 is not prime (divisible by 2)
- 5 is prime
- 6 is not prime (divisible by 2 and 3)
- 7 is prime
- 8 is not prime (divisible by 2 and 4)
- 9 is not prime (divisible by 3)

Thus, the prime numbers in [tex]\(A\)[/tex] are:
[tex]\[ Q = \{2, 3, 5, 7\} \][/tex]

4. Set [tex]\(R\)[/tex]: elements of [tex]\(A\)[/tex] that are even numbers

A number is even if it is divisible by 2. We check each element of [tex]\(A\)[/tex] to see if it is even:
- 1 is not even
- 2 is even
- 3 is not even
- 4 is even
- 5 is not even
- 6 is even
- 7 is not even
- 8 is even
- 9 is not even

Thus, the even numbers in [tex]\(A\)[/tex] are:
[tex]\[ R = \{2, 4, 6, 8\} \][/tex]

Hence, we have determined the elements of the sets as follows:
[tex]\[ P = \{1, 3, 5, 7, 9\} \][/tex]
[tex]\[ Q = \{2, 3, 5, 7\} \][/tex]
[tex]\[ R = \{2, 4, 6, 8\} \][/tex]