**IMPORTANT FACTS**

The price, at which an article is purchased, is called its cost price, abbreviated as C.P.

2. Selling Price:

The price, at which an article is sold, is called its selling prices, abbreviated as S.P.

3. Profit or Gain:

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

4. Loss:

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

**IMPORTANT FORMULAE**

2. Loss = (C.P.) - (S.P.)

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

4. Gain Percentage: (Gain %)

Gain % =[(Gain x 100)/C.P]

5. Loss Percentage: (Loss %)

Loss % = [(Loss x 100)/C.P]

6. Selling Price: (S.P.)

SP = {[(100 + Gain %)/100] x C.P}

7. Selling Price: (S.P.)

SP = {[(100 - Loss %)/100] x C.P}

8. Cost Price: (C.P.)

CP = {[100/(100 + Gain %)] x S.P}

9. Cost Price: (C.P.)

CP = {[100/(100 - Loss %)] x 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 and 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]%.