Given the sets [tex]\( M = \{ \text{prime numbers less than 10} \} \)[/tex] and [tex]\( N = \{ \text{odd numbers less than 10} \} \)[/tex]:

(a) What is the type of the relation between set [tex]\( M \)[/tex] and set [tex]\( N \)[/tex]?

(b) How many improper subsets can be formed from set [tex]\( M \)[/tex]?

(c) How many proper subsets can be formed from set [tex]\( N \)[/tex]?



Answer :

Sure, let's go through each part of the question step by step to understand how to arrive at the solution.

### (a) Type of the Relation Between Set [tex]\( M \)[/tex] and Set [tex]\( N \)[/tex]

First, let's identify the elements of the sets [tex]\( M \)[/tex] and [tex]\( N \)[/tex]:

- [tex]\( M = \{ \text{prime numbers less than 10} \} = \{2, 3, 5, 7\} \)[/tex]
- [tex]\( N = \{ \text{odd numbers less than 10} \} = \{1, 3, 5, 7, 9\} \)[/tex]

We need to determine the type of the relation between these sets. Specifically, we look for common elements between the sets:

- [tex]\( M \cap N = \{3, 5, 7\} \)[/tex]

There are common elements between sets [tex]\( M \)[/tex] and [tex]\( N \)[/tex]. Since the intersection of the two sets is not empty, the relation between set [tex]\( M \)[/tex] and set [tex]\( N \)[/tex] is an intersection.

Answer: The type of relation between set [tex]\( M \)[/tex] and set [tex]\( N \)[/tex] is an intersection.

### (b) Number of Improper Subsets of Set [tex]\( M \)[/tex]

An improper subset of a set is a subset that includes the set itself. In other words, a subset which is not proper because it is exactly the original set.

For set [tex]\( M \)[/tex], the only improper subset is the set [tex]\( M \)[/tex] itself.

Answer: There is 1 improper subset of set [tex]\( M \)[/tex].

### (c) Number of Proper Subsets of Set [tex]\( N \)[/tex]

A proper subset of a set is a subset that does not include the set itself, i.e., it is strictly smaller.

For a set with [tex]\( n \)[/tex] elements, the total number of subsets is [tex]\( 2^n \)[/tex]. However, one of these subsets is the set itself, which is not considered a proper subset.

First, we count the number of elements in set [tex]\( N \)[/tex]:

- [tex]\( |N| = 5 \)[/tex]

The total number of subsets of [tex]\( N \)[/tex] is [tex]\( 2^5 = 32 \)[/tex].

Since we exclude the set itself to count only the proper subsets:

- Number of proper subsets of [tex]\( N = 32 - 1 = 31 \)[/tex]

Answer: There are 31 proper subsets of set [tex]\( N \)[/tex].

Putting it all together:

(a) The relation between set [tex]\( M \)[/tex] and set [tex]\( N \)[/tex] is an intersection.
(b) The number of improper subsets of set [tex]\( M \)[/tex] is 1.
(c) The number of proper subsets of set [tex]\( N \)[/tex] is 31.