Solution

If the cost price of the article is Rs. 40000. An article is marked (p+15)% above its cost price. MRP of the article = 40000 of [100+(p+15)]% = 40000 of [115+p]% = 40000 x (115+p)/100 = 400(115+p) While selling the same article (p-20)% discount was given on it. Selling price of the article = 400(115+p) of [100-(p-20)]% = 400(115+p) of [100-p+20]% = (46000+400p) of [100-p+20]% = (46000+400p) of (120-p)% = (46000+400p) of (120-p)% = [(46000+400p) x (120-p)]/100 = [(460+4p) x (120-p)] The amount of discount given on the article while selling is double the amount of profit earned while selling the same article. 400(115+p) - [(460+4p) x (120-p)] = 2 x [[(460+4p) x (120-p)]-40000] After solving the above equation, there will be two values of ‘p’. One of them is positive and the other one is negative. As we know that the negative value of ‘p’ is not possible. So the value of ‘p’ = 45