GIVEN: Loss = 20% when SP = Rs. 2000 FORMULA USED: Profit = [(SP - CP)/CP] × 100 Loss = [(CP - SP)/CP] × 100 CALCULATION: Since loss is of 20% we can calculate CP as: 20=[(CP−2000)/CP]×100 ⇒ CP =2000/0.8=2500 Now he sells the pen at Rs. 2250: So, Loss % =[(2500−2250)/2500]×100 =25000/2500 Loss % = 10%