**(i)** Given that,

{3, 6, 9, 12}

To represent the given set in the set builder form

In set builder form, all the elements of a set possess a single common property which is not possessed by any element outside the set.

From the given set, we observe that the numbers in the set are multiple of 3 from 1 to 4

such that {x: x = 3n, n ∈ N and 1 ≤ n ≤ 4}

{3, 6, 9, 12} = {x: x = 3n, n ∈ N and 1 ≤ n ≤ 4}

**(ii)** Given that,

{2, 4, 8, 16, 32}

To represent the given set in the set builder form

In set builder form, all the elements of a set possess a single common property which is not possessed by any element outside the set.

From the given set, we observe that the numbers in the set are powers of 2 from 1

to 5 such that {x: x = 2^{n}, n ∈ N and 1 ≤ n ≤ 5}

{2, 4, 8, 16, 32} = {x: x = 2^{n}, n ∈ N and 1 ≤ n ≤ 5}

**(iii)** Given that,

{5, 25, 125, 625}

To represent the given set in the set builder form

In set builder form, all the elements of a set possess a single common property which is not possessed by any element outside the set.

From the given set, we observe that the numbers in the set are powers of 5 from 1 to 4

such that {x: x = 5^{n}, n ∈N and 1 ≤ n ≤ 4}.

{5, 25, 125, 625} = {x: x = 5^{n}, n ∈N and 1 ≤ n ≤ 4}.

**(iv)** Given that,

{2, 4, 6 …}

To represent the given set in the set builder form

From the given set, we observe that the numbers are the set of all even natural numbers.

{2, 4, 6 …} = {x: x is an even natural number}

**(v)** Given that,

{1, 4, 9 … 100}

To represent the given set in the set builder form

From the given set, we observe that the numbers in the set squares of numbers form1 to 10

such that {x: x = n^{2}, n ∈ N and 1 ≤ n ≤ 10}.

{1, 4, 9 … 100} = {x: x = n^{2}, n ∈ N and 1 ≤ n ≤ 10}.

Find the symmetric difference A Δ B, when A = {1, 2, 3} and B = {3, 4, 5}.