If ‘A’ stands for ‘÷’ , ‘B’ stands for ‘×’, ‘C’ stands for ‘+’ and ‘D’ stands for ‘−’ , what will come in place of the question mark ‘?’ in the following equation? 9 B 4 D 18 A 9 C 12 = ?

If 'A' stands for '÷', 'B' stands for '×', 'C' stands for '+' and 'D' stands for '-', what will come in place of the question mark (?) in the following equation? 159 C 60 A 12 B 11 D 203 = ?

What will come in place of '?' in the following equation, if '+' and '-' are interchanged and '×' and '÷' are interchanged? 33 + 31 × 31 ÷ 2 - 49 = ?