Which two numbers should be interchanged so that the value of the given expression becomes correct? 15 - 24 + 63 ÷ 7 × 2 = 9

What will come in place of the question mark (?) in the following equation, if '+' and '-' are interchanged and '×' and '÷' are interchanged? 37 ÷ 5 - 91 + 16 × 4 = ?

If '+' and '-' are interchanged, and '×' and '÷' are interchanged, then what will come in place of the question mark (?) in the following equation? 26 ÷ 676 × 156 - 69 + 83 = ?