Consider the sets below.

[tex]\[ U = \{ x \mid x \text{ is a real number} \} \][/tex]
[tex]\[ A = \{ x \mid x \text{ is an odd integer} \} \][/tex]
[tex]\[ R = \{ x \mid x = 3, 7, 11, 27 \} \][/tex]

Is [tex]\( R \subset A \)[/tex]?

A. Yes, because all the elements of set [tex]\( R \)[/tex] are in set [tex]\( A \)[/tex].
B. No, because each element in set [tex]\( A \)[/tex] is not represented in set [tex]\( R \)[/tex].
C. No, because each element in set [tex]\( R \)[/tex] is not represented in set [tex]\( A \)[/tex].



Answer :

To determine whether [tex]\( R \subset A \)[/tex] (i.e., [tex]\( R \)[/tex] is a subset of [tex]\( A \)[/tex]), we need to check if every element in set [tex]\( R \)[/tex] is also an element in set [tex]\( A \)[/tex].

Given sets:
1. [tex]\( A = \{ x \mid x \text{ is an odd integer} \} \)[/tex]
2. [tex]\( R = \{3, 7, 11, 27\} \)[/tex]

Step-by-Step Solution:

1. List the elements of set [tex]\( R \)[/tex]:
[tex]\[ R = \{3, 7, 11, 27\} \][/tex]
2. Recognize the definition of set [tex]\( A \)[/tex]:
[tex]\[ A = \{ x \mid x \text{ is an odd integer} \} \][/tex]
This means [tex]\( A \)[/tex] contains all odd integers.

3. Determine if each element in [tex]\( R \)[/tex] is in [tex]\( A \)[/tex]:

- [tex]\( 3 \)[/tex]: This number is an odd integer and is therefore in [tex]\( A \)[/tex].
- [tex]\( 7 \)[/tex]: This number is an odd integer and is therefore in [tex]\( A \)[/tex].
- [tex]\( 11 \)[/tex]: This number is an odd integer and is therefore in [tex]\( A \)[/tex].
- [tex]\( 27 \)[/tex]: This number is an odd integer and is therefore in [tex]\( A \)[/tex].

Since all the elements in [tex]\( R \)[/tex] (i.e., 3, 7, 11, 27) are indeed odd integers, they all belong to set [tex]\( A \)[/tex].

Thus, every element of [tex]\( R \)[/tex] is contained in [tex]\( A \)[/tex], meaning [tex]\( R \)[/tex] is a subset of [tex]\( A \)[/tex], or [tex]\( R \subset A \)[/tex].

The correct answer is:
[tex]\[ \text{yes, because all the elements of set } R \text{ are in set } A \][/tex]