**(i)** Given that,

A = \(\{1,2,\{3,4\},5\}\)

To find if {1, 2, 5} ⊂ A is correct or incorrect.

A set A is said to be a subset of B if every element of A is also an element of B

A⊂ B if a ∈ A,a ∈ B

From the above statement,

The each element of \( \{1,2,5\}\) is also an element of A, So \( \{1,2,5\}\)⊂ A

The given statement \( \{1,2,5\}\)⊂ A is a correct statement

**(ii)** Given that,

A = \( \{1,2,\{3,4\},5\}\)

To find if \( \{1,2,5\}∈ A\) A is correct or incorrect.

From the above statement,

Element of \( \{1,2,5\}\) is not an element of A, So \( \{1,2,5\}∉ A\)

So the given statement \( \{1,2,5\}∈ A\) is an incorrect statement.

**(iii)** Given that,

\( \{1,2,\{3,4\},5\}\)

To find if \( \{1,2,3\}⊂A\) is correct or incorrect.

A set A is said to be a subset of B if every element of A is also an element of B

A⊂ B if a ∈ A,a ∈ B

From the above statement, we notice that,

3 ∈ {1, 2, 3}; where, 3 ∉ A.

\( \{1,2,3\} \nsubseteq A\)

The given statement \( \{1,2,3\}⊂A\) is an incorrect statement.

**(iv)** Given that,

\( \{1,2,\{3,4\},5\}\)

To find if Φ ∈ A is correct or incorrect.

A set A is said to be a subset of B if every element of A is also an element of B

A⊂ B if a ∈ A,a ∈ B

From the above statement,

Φ is not an element of A. So, Φ ∈ A.

The given statement Φ ∈ A is an incorrect statement.

**(v)** Given that,

\( \{1,2,\{3,4\},5\}\)

To find if Φ ⊂ A is correct or incorrect

A set A is said to be a subset of B if every element of A is also an element of B

A⊂ B if a ∈ A,a ∈ B

From the above statement,

Since Φ is a subset of every set, Φ ⊂ A

The given statement Φ ⊂ A is a correct statement.

**(vi) **Given that,

**\( \{1,2,\{3,4\},5\}\)**

To find if {Φ} ⊂ A is correct or incorrect.

A set A is said to be a subset of B if every element of A is also an element of B

A⊂ B if a ∈ A,a ∈ B

From the above statement,

Φ is an element of A and it is not a subset of A.

The given statement {Φ} ⊂ A is an incorrect statement.

Answered by Abhisek | 1 year agoFind the symmetric difference A Δ B, when A = {1, 2, 3} and B = {3, 4, 5}.