⇒ Let the cost price of article for A be Rs. x and he sells it at 20% profit to B ⇒ Selling Price of article by A is the cost price for B ⇒ Selling Price of article by A = x + 20% of x = cost price for B ⇒ Cost price of article for B = 1.2 x ⇒ B sell that to C at 25% profit and C pays 1800 ⇒ Selling Price for B = cost Price of C = 1800 ⇒ Selling Price for B = 1.2 x + 25% of 1.2 x = 1800 ⇒ 1.5 x = 1800 ∴ x = Rs. 1200