यदि `A ={1,2,{2,3},4}` बताइये कथन सत्य है ?
`{(2,3)} sub A`

Let A = {1, 2, 3, 4}, B = {1, 2, 3} and C = {2, 4}. Find all sets X satisfying pair of conditions : X sub A, X sub B and X sub C .

Let A = {1, 2, 3, 4}, B = {1, 2, 3} and C = {2, 4}. Find all sets X satisfying pair of conditions : X sub B and X cancel (sub) C .

Let A ={1,2,{3,4},5} . Which of the following statements are incorrect and why ? (i) {3,4} subA (ii) {3,4} in A (iii) {{3,4}}sub A (iv) 1 in A (v) 1 sub A (vi) {1,2,5} sub A (vii) {1,2,5} in A (viii) {1,2,3} sub A (ix) phi in A (x) phi sub A (xi) {phi} sub A .

Let A ={1,2,{3,4},5} . Which of the following statements are incorrect and why ? (i) {3,4} subA (ii) {3,4} in A (iii) {{3,4}}sub A (iv) 1 in A (v) 1 sub A (vi) {1,2,5} sub A (vii) {1,2,5} in A (viii) {1,2,3} sub A (ix) phi in A (x) phi sub A (xi) {phi} sub A .

Let A ={1,2,{3,4},5} . Which of the following statements are incorrect and why ? (i) {3,4} subA (ii) {3,4} in A (iii) {{3,4}}sub A (iv) 1 in A (v) 1 sub A (vi) {1,2,5} sub A (vii) {1,2,5} in A (viii) {1,2,3} sub A (ix) phi in A (x) phi sub A (xi) {phi} sub A .

If R is the smallest equivalence relation on the set {1, 2, 3, 4} such that {(1,2), (1,3)}sub R , then the number of elements in R is ______