Concept of Discount

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

A watch priced at Rs.160 is sold for Rs.140. Find the 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 washing 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