Given: Dealer sells the goods at a loss of 641​% on cost price He uses 14 gms instead of 16 gmsCalculation: Let the cost of the goods be Rs. 1 per gm. ⇒ CP of 16 gms = Rs. 16 He sells the goods at 425​% loss on cost price. ⇒ SP of 16 gm of goods =16−4×10016×25​=16−1= Rs. 15 He also used 14 gms instead of 16 gms. ⇒ He takes Rs. 16 instead of Rs. 14 from the customer. ⇒ Profit of the shopkeeper = (16 – 15) = Rs. 1 ⇒ profit % =141​×100=750​%∴ Gain percent of the shopkeeper = 771​%