Question

The smallest set A such that A ∪ {1, 2} = {1, 2, 3, 5, 9} is

• A. {2, 3, 5}
• B. {3, 5, 9}
• C. {1, 2, 5, 9}
• D. None of these

Answer 1

Answer: (B)

{3, 5, 9}

Answer 2

Given $A \cup \{ 1,2 \} = \{ 1,2,3,5,9 \}$ . Hence, $A = \{ 3,5,9 \}$.