LOST = 20%After selling the watch again = Rs 1472Formula required:COST price = selling price + lossCalculation:20% LOSS + selling price = 100% of cost price ⇒ 1024 = 100% cost price - 20% loss ⇒ 1024 = 80% of cost price (∵ loss on cost price 20% of cost price)The cost price of the watch = 1024 × (100/80)⇒ 1280Profit = selling price - cost price ⇒ 1472 - 1280 =192Percentage profit = (192/1280) × 100⇒ 15%∴ The percentage profit is 15%At 20% loss, Ratio between C.P and S.P = 5 : 4Given 4 unit = 1024 ∴ 5 unit = (1024/4) × 5 = Rs. 1280 = C.PNew S.P = Rs. 1472⇒ Profit % = [(1472 - 1280)/1280] × 100 ⇒ Profit % = (192/1280) × 100 = 15%∴ The percentage profit is 15%