Question

M ∪ N = {1, 2, 3, 4, 5, 6} and M = {1, 2, 4} then which of the following represent set N ?

Options

• {1, 2, 3} 

• {3, 4, 5, 6}

• {2, 5, 6}

• {4, 5, 6}

Answer 1

We have, M ∪ N = {1, 2, 3, 4, 5, 6} and M = {1, 2, 4}

Since, {1, 2, 3} ∪ {1, 2, 4} = {1, 2, 3, 4} ≠  M ∪ N = {1, 2, 3, 4, 5, 6};

{3, 4, 5, 6} ∪ {1, 2, 4} = {1, 2, 3, 4, 5, 6} = M ∪ N = {1, 2, 3, 4, 5, 6};

{2, 5, 6} ∪ {1, 2, 4} = {1, 2, 4, 5, 6} ≠ M ∪ N = {1, 2, 3, 4, 5, 6}; and

{4, 5, 6} ∪ {1, 2, 4} = {1, 2, 4, 5, 6}  ≠ M ∪ N = {1, 2, 3, 4, 5, 6}