A discount is a deduction in the price of a good or service.

## Formula

Discount $= original$ $price-sale$ $price$

Percentage discount $=\dfrac {discount}{original\hspace{0.1cm}price}\times 100$

### Example 1

A pool store is having an end of financial year sale.

a) What is the discount and percentage discount of a pool reduced to $800 from$950 (to one decimal place)?

Discount $= original$ $price-sale$ $price$
Discount $= 950-800$
Discount $= 150$

Percentage discount $=\dfrac {discount}{original\hspace{0.1cm}price}\times 100$
Percentage discount $=\dfrac {150}{950}\times 100$
Percentage discount $=15.789$

The pool is discounted by $150 and is reduced by 15.8% b) What is the original price of a pool if it has been reduced by 20% and is on sale for$700?

We know that the pool has been discounted by 20%, so the sale price must be 80% of the original price.

Sale price is 80% of $x$ $700=80%$ of $x$ $700=\frac {80}{100}\times x$ $700=0.8x$ $x=875$

The original price of the pool was \$875.