The given sets in set – builder form are

(i) {x : x = 3n, n ∈ N,n < 5}

(ii) {x : x = 2n,n ∈ N,n < 6}

(iii) {x : x = 5n,n ∈ N, n < 5}

(iv) {x : x is an even natural number}

(v) {x : x = n^{2},n ∈ N,n ≤ 10} (vi) {x : x = n^{2},n ∈ N}

(vii) {x : x = n/(n + 1), n ∈ N, n < 7}