Concept of Discount

It is usually seen that the retailers cannot sell defective items, old items, etc. at the retail-selling price. If these items are sold at lower price, then it is called sale price.
\therefore  The difference between marked price (selling price) and the sale price, is called discount.
In other words, a reduction in the price of an article for payment in cash is called discount.
Hence \boxed{{\text{Discount =  Marked Price - Sale Price}}}
Discount is usually given as a percentage of the original price.

A watch priced at Rs.160 is sold for Rs.140. Find percentage discount.
Let       Marked Price = Rs.160
            Sale Price = Rs.140
            Discount = Marked Price – Sale Price = 160 – 140 = Rs.20
            Percentage Discount = \frac{{20}}{{160}} x 100 = 12\frac{1}{2}\%
The marked price of a machine is Rs.600. A discount of 6% is given during a sale. What is the sale price of the washing machine?

Let       Marked Price = Rs.600
            Discount Rate = 6%
            Discount = 6% of the marked price = \frac{6}{{100}}x 600 = Rs.36
            \therefore  Sale Price = Marked Price – Discount = 600 – 36 = Rs.564