Simplify the following:
18 - [6 – {4 - (8 - 6 + 3)}]

Correct option is D

Given:

18 - [6 – {4 - (8 - 6 + 3)}]

Concept Used:

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

Solution:

18 - [6 – {4 - (8 - 6 + 3)}]

=18 - [6 – {4 - (11 - 6)}]

=18 - [6 – {4 - 5}]

=18 - [6 – {-1}]

=18 - [6 + 1]

=18 - 7

=11

Option (D) is right.