One of the most important numbers that all businesses want to know about is their **profit** (or if things are not going so well, their **loss**).

Profit (on an individual sale) is simply the amount that something is sold for (the **selling price**) minus the amount it cost (the **cost price**).

So if a bicycle cost $315 to make and sells for $500, what will be the profit on it. If it goes out of fashion and has to be sold for only $300, what will be the profit on it?

**Exercise**

Let’s complete exercises 16A and 16B from pages 266 and 267 of the textbook:

The answers are below:

**Percentage profit**

If a business is selling lots of different things, they might be interested in the **percentage profit** of each of the goods they sell. This can help them decide which goods to spend more effort marketing.

We can calculate percentage profit using the following formula:

So, if we bought an item for $20 and sold it for $35, what would be our percentage profit?

**Examples**

**Exercise**

Let’s complete exercise 16C from page 267 of the textbook:

The answers are below:

**Selling Price**

We can also do calculations the other way round. That is, if we know how much something cost and we know the percentage profit, we can then work out what price it was sold at.

**Example**

**Exercise**

Let’s complete exercise 16D on pages 268 and 269 of the textbook:

The answers are below: