Published: 05 Aug 2019

**Cost price (C.P.) :** This is the price at which an article is purchased.

**Selling price(S.P.) :** The price at which an article is sold, is called its **selling price, **

**Profit or Gain :** If S.P. is greater than C.P. , the seller is said to have a **profit or gain.**

**Loss :** If S.P. is less than C.P., the seller is said to have incurred a **loss.**

· Profit or Loss is always calculated on the cost price.

· Marked price: This is the price marked as the selling price on an article, also known as the listed price.

· Discount or Rebate: This is the reduction in price offered on the marked or listed price.

Below is the list of some basic formulas used in solving questions on profit and loss:

1. Gain = (S.P.) – (C.P.)

2. Loss = (C.P) – (S.P.)

3. Loss or gain is always reckoned on C.P.

4. Gain% = (Gain X 100/C.P)

5 Loss% = (Loss X 100/C.P)

6. S.P. = (100 + Gain%)/100 × C.P.

7. S.P. = (100 + Loss%)/100 × C.P.

8. C.P. = 100/(100 + Gain%) × S.P.

9. C.P. = 100/(100 - Loss%) × S.P.

10. If an article is sold at a gain of say, 35%, then S.P. = 135% of C.P.

11. If an article is sold at a loss of say, 35%, then S.P. = 65% of C.P.

12. When a person sells two similar items, one at a gain of say, x% and the other at a loss of x%, then the seller always incurs a loss given by :

Loss% = (common Loss Gain%/10)^{2} = (x/10)^{2}

13. If a trader professes to sell his goods at cost price, but uses false weights, then

Gain% = [Error/ (True value) - (Error) X 100]%