What is the profit if the cost is $30 and the selling price is $50?

To find the profit, you can use the formula:

Profit = Selling Price - Cost

In this scenario, the selling price is $50 and the cost is $30. By plugging these values into the formula, we get:

Profit = $50 - $30 = $20.

This calculation shows that the profit, which is the amount earned after covering the costs, is indeed $20. This result aligns directly with the information given in the question and confirms that the selling price exceeds the cost by that amount, representing a successful transaction where a surplus is generated.