If 'A' stands for '÷', 'B' stands for '×', 'C' stands for '+' and 'D' stands for '-', what will come in place of question mark '?' in the following equation? 94 C 16 B 5 D 12 A 6 = ?

If '+' is interchanged with '-' and '×' is interchanged with '÷', what will come in place of '?' in the following equation? 529 ÷ 23 + 89 - 12 × 9 = ?

By interchanging which two signs will the given equation become correct? 15 - 9 ÷ 6 × 10 + 5 = 25