Which two signs should be interchanged to make the following equation correct?

33 + 4 × 21 ÷ 3 − 17 = 122

33 + 4 × 21 ÷ 3 − 17 = 122​

Logic: interchange mathematical operators and solve as per BODMAS rule.

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

Check option A,– and ×

33 + 4 × 21 ÷ 3 − 17 = 122

After interchanging,

33 + 4 - 21 ÷ 3 × 17 = 122

37 - 21 × 17 = 122

37 - 357 = 122

-320≠122

So, its not correct option.

Check option B, ÷ and –

33 + 4 × 21 ÷ 3 − 17 = 122

After interchanging,

33 + 4 × 21 - 3 ÷ 17 = 122

Here, 3 is perfectly not divisible by 17.

So, its not correct option.

Check option C,+ and ×

33 + 4 × 21 ÷ 3 − 17 = 122

After interchanging,

33 × 4 + 21 ÷ 3 − 17 = 122

132 + 7 − 17 = 122

122=122

Check option D,+ and –

33 + 4 × 21 ÷ 3 − 17 = 122

After interchanging,

33 - 4 × 21 ÷ 3 + 17 = 122

50 - 4 × 7 = 122

50 - 28 = 122

22≠122

So, its not correct option.

Thus, correct option is (c).