What will come in the place of the question mark '(?)' in the following equation, if  '×' and '+' are interchanged and '-' and '÷' are interchanged

57 ÷ 9 × 50 - 5 + 2 = ?

If '+' stands for multiplication, '<' stands for division, ' ÷' stands for subtraction, '-' stands for addition and '×' stands for greater than, which expression is correct

If 'A' means '÷', 'B' means 'x', 'C' means '+' and 'D' means '−', then what will come in place of the question mark (?) in the following equation?
(80 A 8) B 5 C 14 B 2 D 11 B 3 C 72 A4 = ?

If ‘A’ stands for ‘÷’ , ‘B’ stands for ‘x’, ‘C’ stands for ‘+’ and ‘D’ stands for ‘-‘ , what will be come in place of question mark ‘?’ in the following equation?
16 B 4 D 56 A 2 C 7 = ?

If ‘A’ stands for ‘÷’ , ‘B’ stands for ‘x’, ‘C’ stands for ‘+’ and ‘D’ stands for ‘-‘ , what will be come in place of question mark ‘?’ in the following equation?
19 B 3 D 18 A 6 C 5 = ?

If ‘+’ means ‘−’, ‘−’ means ‘×’, ‘×’ means ‘÷’ and ‘÷’ means +’, then what will come in place of the question mark (?) in the following equation?
88 − 9 ÷ 195 + 988 × 19 = ?

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?
216 C 22 B 12 D 424 A 4=?

If A means '+ ', B means '- ', C means '×' and D means ' ÷', then what will come in place of the question mark (?) in the following equation?
10 A 30 D 6 B 2 C 3 = ?

If ‘+’ means ‘subtraction’, ‘−’ means ‘multiplication’, ‘×’ means ‘division’ and ‘÷’ means ‘addition’, then what will come in place of the question mark (?) in the following equation?
64 × 8 + 6 − 6 ÷ 33 = ?

If + means −, − means ×, × means ÷ and ÷ means +, then what will come in place of the question mark (?) in the following equation?
75 × 5 + 11 − 2 ÷ 18 = ?