By interchanging the given two signs and numbers which of the following equation will be not correct?
– and ÷, 8 and 2
I. 5 + 7 – 8 × 4 ÷ 2 = 9
II. 3 + 8 × 4 – 2 ÷ 1 = 3

Given: Interchange:

‘–’ and ‘÷’

‘8’ and ‘2’

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

I. 5 + 7 – 8 × 4 ÷ 2 = 9
After interchanged equation will be:

5 + 7 ÷ 2 × 4 – 8 = 9

5 + 3.5 × 4 – 8 = 9

5 + 14 - 8 = 9

19 - 8 = 9

11 $$\not=$$ 9​

After interchanged equation will be:

3 + 2 × 4 ÷ 8 – 1 = 3

3 + 1 - 1

? = 3 = 3

So, only I is not correct.

Thus, the correct option is: (d)