What will come in place of the question mark (?) in the following equation, if ' + ' is interchanged with ' x ', and ' ÷ ' is interchanged with '-'?
6÷16×4÷8-8+2×7=" ? "

Equation: 6 ÷ 16 × 4 ÷ 8 - 8 + 2 × 7

BODMAS rule (Bracket, Orders (i.e., powers and square roots, etc.), Division and Multiplication, Addition and Subtraction);

​$$\begin{array}{|c|c|} \hline \textbf{Operation preference wise} & \textbf{Symbol} \\\hline Brackets &[],{}, () \\ \hline Orders, of & (power), √ (root) , of \\ \hline Division& ÷ \\ \hline Multiplication & × \\ \hline Addition & + \\ \hline Subtraction & - \\\hline \end{array}$$​​

Solution:
' + ' is interchanged with ' x ', and '÷' is interchanged with '-'
New equation: 6 - 16 + 4 - 8 ÷ 8 × 2 + 7

= 6 - 16 + 4 - 1 × 2 + 7

= 6 - 16 + 4 - 2 + 7

= -1

Thus, correct option is (c).