Correct Answer - Option 2 : 50%

**Given: **

Notebooks sold = 12

Profit = Selling price of 4 notebooks

**Formula Used:**

Selling price = Cost price + Profit

Profit% = \(\frac{Profit}{Cost\space Price} × 100\)

**Calculation:**

Let assume that the selling price of 1 notebook is 'SP'

And cost price of 1 notebook is 'CP'

The selling price of 12 notebooks = 12 SP

The cost price of 12 notebooks = 12 CP

According to the question:

Profit = Selling Price - Cost Price

⇒ 4 SP = 12 SP - 12 CP

⇒ CP/SP = 2/3

CP = 2 units

SP = 3 units

Profit = 1 unit

Now,

⇒ Profit% = 1/2 × 100

⇒ Profit% = 50%

∴ Profit% is 50%

The correct option is 2 i.e. 50%