Cost Price

The price at which an article is purchased is called the cost price or CP.

Selling Price

The price at which an article is sold is called the selling price or SP.s

Formulae

Gain or Profit = SP – CP

Marked Price or List Price

Price that is indicated or marked on the article is called marked price or MP.

Discount

It is reduction given on the Marked Price or List Price of an article.

If a trade gets x% profit and x% loss in selling two different articles, then in over all transaction, there is always a loss which is given by

Example 3: A book is bought for Rs. 80 and sold at the gain of 5%. Find the selling price.

Solution. CP = Rs. 80, Gain = 5%

Example 4: If cost price of 15 articles is equal to the selling price of 12 articles, then find the gain per cent.

Solution. Let cost price of each article = Rs. 1
             Then, Cost price of 15 articles = Rs. 15
                    Selling price of 12 articles = Rs. 15
                 But Cost price of 12 articles = Rs. 12
                                                    Profit = Rs. (15 – 12) = Rs. 3

Example 7: A radio is listed at Rs. 500 with a discount of 10%.What additional discount must be offered to the customer to bring the net price to Rs. 423?

Solution. List price = Rs. 500, Discount = 10%