Important Formulae

Today we'll explore the concepts of profit and loss. Who can tell me what profit is?

Profit is what you make after selling something for more than you bought it!

Exactly! Profit can be calculated using the formula $Profit = S.P. - C.P.$. How about loss? What does that mean?

Loss is when you sell something for less than you bought it!

Correct! Loss is calculated using $Loss = C.P. - S.P.$. Remember this with the mnemonic 'CPSP' – Cost Price minus Selling Price equals Loss!

Can you give us an example?

Sure! If you bought an item for $50 and sold it for $40, your loss is $50 - 40 = 10$. That's a loss of $10.

What's the formula for calculating the profit percentage?

Great question! The formula is $Profit\% = \frac{Profit}{C.P.} \times 100$. So if we made a profit of $10 on a CP of $50, it would be $\frac{10}{50} \times 100 = 20\%$.

In summary, profit is what you earn, loss is what you lose, and we can quantify these with percentages!

Now let's discuss selling price (S.P.) and cost price (C.P.). How can we calculate S.P. when we have profit?

You would add the profit to the cost price!

Exactly! The formula is $S.P. = C.P. + Profit$. What about calculating C.P. when we have loss?

You subtract the loss from the selling price.

Right! The formula is $C.P. = S.P. + Loss$. A good way to remember this: 'Add what you gain, subtract what you lose.'

What if we want to find out the cost price from selling price with profit?

When you have profit, the formula is $C.P. = S.P. - Profit$. These formulas help us calculate the financial outcomes of our transactions!

In summary, selling price can be calculated by adding profit and cost price, while cost price can be derived by subtracting loss or profit from selling price.

Let's move on to discounts! Can someone explain what a discount is?

A discount is a reduction from the marked price!

Correct! The formula for calculating discount is $Discount = M.P. - S.P.$. What about finding the discount percentage?

That's $Discount\% = \frac{Discount}{M.P.} \times 100$!

Exactly! To remember this, think of 'How much off is the price?' That connects us to the discount percentage formula.

Can we have an example of a discount calculation?

Certainly! If an item has a marked price of $100 and is sold for $80, what's the discount?

It's $20!

Correct! And the discount percentage is $\frac{20}{100} \times 100 = 20\%$.

So remember to calculate both the discount value and its percentage to gauge savings effectively!