Profit and Loss:

1.gain=s.p-c.p

2.loss= -(s.p-c.p)

3.gain= -loss

4.(gain||loss)%=[(gain||loss)x100]/C.P

5.S.P=[(100+gain%)xC.P]/100

6.if an article is sold at a gain of  p% ten S.P=(100+p)% of C.P 

7.if an article is sold at a loss of  p% ten S.P=(100-p)% of C.P 

8.when a person sells two similaritems,ane at a  gain of p%,and the other at a loss of p%,then seller always incurs a loss given by:

Loss%=(p/10)^2

9.if a trader professes to sell his goods at coast price,but uses false weights,then

Gain%=[{(false gain i.e Error)x100}/(true value-Error)]%