Simplify: $$65 - [40 - (60 \div 5 - (18 - 24 \div 4) \div 6)]$$​​

Correct option is D

Given: 

65 − [40 − (60 ÷ 5 − (18 − 24 ÷ 4) ÷ 6)]  

Concept Used: 

​$$\begin {array}{|c|c|} \hline \textbf{Operation preference wise} & \textbf{Symbol} \\ \hline Brackets &[],{}, () \\ \hline Orders, of & ² (power), √ (root) , of \\ \hline Division & ÷ \\ \hline Multiplication & × \\ \hline Addition & + \\ \hline Subtraction & - \\ \hline \end{array}$$

Solution:  

65 − [40 − (60 ÷ 5 − (18 − 24 ÷ 4) ÷ 6)]  

$$\begin{aligned}= & 65 - \left[ 40 - \left( \frac{60}{5} - \frac{ \left( 18 - \frac{24}{4} \right)}{6} \right) \right] \\&= 65 - \left[ 40 - \left( 12 - \frac{(18 - 6)}{6} \right) \right] \\&= 65 - \left[ 40 - \left( 12 - \frac{12}{6} \right) \right] \\&= 65 - \left[ 40 - (12 - 2) \right] \\&= 65 - [40 - 10] \\&= 65 - 30 \\&= 35\end{aligned}$$​