The Marked Price of 1 kg tomatoes was ₹ 20. The shopkeeper started selling the tomatoes @ ₹ 13 per kg. The Discount percentage given by the shopkeeper is
MP = ₹ 20
SP = ₹ 13
Discount = ₹ 20 - ₹ 13 = ₹ 7
Discount % = DiscountMP×100 = 720×100 = 35%