What will come in place of the question mark (?) in the following equation, if ‘+’ and ‘–’ are interchanged, and ‘×’ and ‘÷’ are interchanged?
87 × 3 ÷ 4 + 12 – 30 = ?​

 Given: 87 × 3 ÷ 4 + 12 – 30 = ?

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

New equation: 87 ÷ 3 × 4 – 12 + 30 = ?

29 × 4 – 12 + 30 = ?

116 – 12 + 30 = ?

146 – 12 = ?

Thus, correct option is (a).​