Explanation:

Correct Option is : 4- 40%

The retailer gives the discount scheme of buy 3, get 2 free
Solution
Total number of shirts given by the seller in the price of 3 = 3 + 2 = 5 pieces
Let the selling price of each shirt be Rs. 100
So, selling price of 5 = 100 x 5 = Rs. 500
Here the seller has given 5 shirts at the price of 3
So, actual amount which seller got = 3 x 100 = Rs. 300
So, discount amount = 500-300 = Rs. 200
Discount % (200/500) > 100
⇒ 40
So, discount % = 40%
: The discount percentage is 40%.