1. Let's start by understanding what percentage profit and loss mean. 2. Percentage profit occurs when the selling price (SP) of an item is more than its cost price (CP). The formula for percentage profit is: $$\text{Percentage Profit} = \left(\frac{\text{Profit}}{\text{Cost Price}}\right) \times 100 = \left(\frac{\text{SP} - \text{CP}}{\text{CP}}\right) \times 100$$ 3. Percentage loss occurs when the selling price is less than the cost price. The formula for percentage loss is: $$\text{Percentage Loss} = \left(\frac{\text{Loss}}{\text{Cost Price}}\right) \times 100 = \left(\frac{\text{CP} - \text{SP}}{\text{CP}}\right) \times 100$$ 4. Important rules: - Profit or loss is always calculated based on the cost price. - If SP > CP, it's a profit; if SP < CP, it's a loss. 5. Example: Suppose an item costs 200 and is sold for 250. Profit = SP - CP = 250 - 200 = 50 Percentage Profit = $$\left(\frac{50}{200}\right) \times 100 = 25\%$$ 6. Example: Suppose an item costs 300 and is sold for 270. Loss = CP - SP = 300 - 270 = 30 Percentage Loss = $$\left(\frac{30}{300}\right) \times 100 = 10\%$$ 7. These formulas help you quickly find how much profit or loss you made as a percentage of the cost price, which is useful for comparing deals or business performance.