A dishonest merchant sells goods at a 12.5 % loss on the cost price, but uses 28 g weight instead of 36 g. What is his percentage profit or loss?

12.5 % gain

Merchant sells goods at a 12.5% loss:

C.P : S.P = 8 : 7

Merchant uses 28 g weight instead of 36 g

C.P : S.P = 28 : 36 = 7 : 9

So, C.P : S.P = 56 : 63 = 8 : 9

Profit% = \(\frac{9 - 8}{8}\) × 100 

⇒ 12.5%