Important Terms
SP – Selling price
CP – Cost price
MP – Marked price
Formulas
Profit = SP – CP Â
Loss = CP – SP
Profit% = ((SP – CP)/CP) * 100
Loss% = ((CP – SP)/CP) * 100
SP = (1+ profit%) * CP
SP = (1 – Loss%) * CP
CP = SP/(1+profit%)
CP = SP/(1-Loss%)
MP = SP+ Discount
MP = SP/(1-Disount%)
Discount% = ((MP – SP) / MP) * 100
Profit% = MP% – Discount% – (MP% * discount%)
If profit and loss are same(x), then loss%= (X/10)2
Problem:
1) A person incurs 5% loss by selling a watch for Rs.1140 at what price should the watch be sold is earn 5% profit?
Solution:
CP = SP/(1-Loss%)
CP = 1140*100/(100-5)
CP = 1200
To incur 5% profit the product should be sold = 1200*105/100
SP = 1260
2) An article sold at a loss of 10%, Its CP is 800. A discount of 20% was offered on the labeled price while selling. What is the loss% at the labeled price?
Solution:
SP = (1- loss%)*CP
SP = 800*90/100 = 720
MP = SP/(1-Disount%)
MP = 720/(1-20%) = (720*100)/80 = 900
Loss % at labeled price = ((MP-SP)/MP)*100
Loss% = ((900-720)/900)*100 = 20%
3) By what percent must the cost price be raised in fixing the sale price in order that there may be a profit of 20% after allowing a commission of 10%.
Solution:
Usual method: CP =100 rs , profit = 20%
                      SP = 120 rs
            Commission 10%, then MP = SP/(1-discount%)
                            MP = 120/(1-10%) = 120/(1-(10/100))
                                               =120* 100/(100-10)  Â
                                               = 133.3 rs
                                     MP% = ((MP- CP)/CP)*100
                                               =33.3%             Â
So MP should be 33.3% more than CP to get 20% profit after allowing commission of 10%
         Shortcut :
Profit%= MP% – Discount% – (MP%*discount%)
Let MP%=x%
20/100 = x/100 – 10/100 – ((x/100)*(10/100))
30/100 = 90x/10000
X = 33.3%
4) The price of land came to a person through three middle man each gaining 20% if the person purchased the land for RS.3,45,600 the original cost of land was ?
Solution :
CP = SP/(1+profit%)
CP =Â 345600*(100/120)*(100/120)*(100/120)
CP = 2,00,000 rs
5) A cloth merchant sold half of his cloth at 20% profit and half of the remaining cloth at 20% loss and remaining at the cost price. In total transmission what will be his gain or loss?
Solution:
Let CP = 100
Half of the cloth at 20% profit, SP = 50 *120/100 = 60
Half of the remaing cloth at 20% loss, SP = 25 *80/100 = 20
Reaming cloth at CP, Therefore SP = 25
On total transaction SP = 60 + 20 +25 = 105
Profit% = 5%