1. Gain = SP – CP

2. Loss = CP – SP

3. Gain on Rs. 100 is Gain per cent

4. Gain% = (Gain * 100)/CP

5. Loss on Rs. 100 is Loss per cent 6. Loss% = (Loss * 100)/CP

7. When the Cost Price and Gain per cent are given: SP = [(100+Gain %)/100] x CP

8. When the Cost Price and Loss per cent are given: SP = [(100-Loss %)/100] x CP

9. When the Selling Price and Gain per cent are given: CP = [100/(100+Gain %)] x SP

10. When the Selling Price and Loss per cent are given: CP = [100/(100-Loss %)] x SP

11. When p articles are sold at the cost of q similar articles, the Profit/Loss % = [(q-p)/p]x100

12. If two articles are sold at the same price with a profit of x % on one and a loss of x % on the other, the net loss % = (x2 /100)%

13. If two articles bought at the same price are sold with a profit of x % on one and a loss of x % on the other, then overall there will be No Profit No Loss