What will the value of the following expression be?
20-[15-{4-(8-6+3)}]

Correct option is B

​Given:

​$$20 - [15 - \{4 - (8 - 6 + 3)\}]$$ 

Concept Used: 

BODMAS rule:

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

Solution:

= $$20 - [15 - \{4 - (8 - 6 + 3)\}]$$​​

= $$20 - [15 - \{4 - 5\}]$$​​

= $$20 - [15 - (-1)]$$​​

= $$20 - [15 + 1]$$​

= 20 - 16

= 4